IELTS Real Reading Test 2026 - Q2 Test 1 with Practice Test, Answers And Explanation
Luyện tập đề IELTS Real Reading Test 2026 - Q2 Test 1 được lấy từ cuốn sách Real Test 2026 - Q2 với trải nghiệm thi IELTS trên máy và giải thích đáp án chi tiết bằng Linearthinking, kèm answer key và list từ vựng IELTS cần học trong bài đọc.
IELTS Real Reading Test 2026 - Q2 Test 1 with Practice Test, Answers And Explanation
Passage
❓ Câu hỏi passage 1
Question 1 - 7
Complete the notes below.
Choose ONE WORD ONLY from the passage for each answer.
Pest control
Early 20th-century problems in Australia
• The larvae of a type of
1.
were a serious pest in sugar cane fields.
• Its larvae ate the
2.
of the plant.
• Chemical pesticides were unsatisfactory because they were:
- poisonous
-
3.
- difficult to remove from the ground
Experiences with biological pest control• The use of insects, plants and birds was widespread.
• In the 19th century French
4.
used toads.
• In Australia a
5.
stopped the spread of prickly-pear cactus.
• Cane toads were brought to Australia from
6.
.
• Cane toads proved to be a
7.
as pest control.
Question 8 - 13
Do the following statements agree with the information given in the Reading Passage?
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if it is impossible to say what the writer thinks about this
8
The outcome of the introduction of cane toads was immediately obvious.
9
Rabbits were introduced to Australia to control weeds.
10
Walter Froggatt was criticised for his efforts to stop the introduction of the cane toad to Australia.
11
The average size of cane toads has increased since their introduction.
12
Australian animals can eat cane toads safely.
13
In many places cane toads are gaining control of the habitats of Australian fauna.
Passage
❓ Câu hỏi passage 2
Question 14 - 21
Reading Passage has six paragraphs A-F.
Which paragraph contains the following information?
Write the correct letter, A-F.
NB You may use any letter more than once.
14
an example of a plant's use of chemicals in its reproductive process
15
how some plants use a kind of glue to discourage attack
16
two examples of non-chemical methods of defence in plants
17
a definition of the term allelopathy
18
descriptions of how plants use chemicals to discourage predators
19
benefits of using plant-based chemicals to control weeds in agricultural areas
20
a description of the characteristics of allelopathic chemicals
21
an example of a physical characteristic that helps one plant conserve water
Question 22 - 25
Do the following statements agree with the information given in the Reading Passage?
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if it is impossible to say what the writer thinks about this
22
The 'hypodermic syringes' of the nettle plant are an example of glandular trichomes.
23
Allelopathic plants grow more successfully than plants that rely only on physical features.
24
New research into synthetic herbicides is largely focused on individual allelopathic chemicals.
25
Herbicides cost Australian farmers over A$200 million a year.
Question 26
Choose the correct letter, A, B, C or D.
Write the correct letter in boxes on your answer sheet.
26
The two main points of this article are that plants can defend themselves in a number of ways, and that
A
combating weeds is a major problem for Australian farmers.
B
considerable research has been carried out into the use of plant chemicals.
C
Australian plants have unique methods of self-protection.
D
chemicals found in weeds can have practical benefits for agriculture.
Passage
❓ Câu hỏi passage 3
Question 27 - 32
Choose the correct letter, A, B, C or D.
Write the correct letter in boxes on your answer sheet.
27
What does the writer say about Dunedin in the 1970s?
A
It was the safest city in the country.
B
It was richer than other cities in the country.
C
Many people were frustrated that they could not find a job.
D
The inhabitants thought they lived in a desirable place.
28
What does the writer find surprising about Phil Silva's original study?
A
So many parents lived in Dunedin.
B
So many children refused to be tested.
C
So many parents were willing to participate.
D
So many tests could be conducted in half a day.
29
What problem did Silva face when conducting the original study?
A
a shortage of helpers
B
a lack of available funding
C
the bad behaviour of some children
D
the poor language skills of the participants
30
What was different about the first and second studies?
A
The two studies produced conflicting results.
B
Helpers were not used in the second study.
C
The sample group was smaller in the first study.
D
The second study collected additional types of information.
31
What was Silva's main finding in 1978?
A
The children had well developed language skills.
B
The incidence of ear problems in children was falling.
C
More frequent medical tests on children were needed.
D
There was a definite risk of eyesight problems in children.
32
The writer refers to the new building in the fourth paragraph in order to
A
illustrate how the study could only find a short-term base.
B
show that the study was being taken seriously for the first time.
C
show how generous project funding had become.
D
emphasise the fact that the children did not think it was big enough.
Question 33 - 36
Do the following statements agree with the information given in Reading Passage?
In following statements below, choose
YES if the statement agrees with the information
NO if the statement contradicts the information
NOT GIVEN if it is impossible to say what the writer thinks about this
33
Recent results suggest that intellectual development and birth weight are linked.
34
Medical textbooks used to claim that breast-fed children were more intelligent.
35
Children who suck their thumbs are prone to developmental problems.
36
The findings of the Dunedin study have challenged some doctors' preconceptions.
Question 37 - 40
Complete the summary using the list of words, A-I, below.
The success of the Dunedin project has been put down to two principal factors: good fortune and Phil Silva’s methodology. The demographics of Dunedin mean that residents feel committed to the study, and that it also provides that can be applied both nationally and internationally. But even more important was Silva’s conviction that the must be looked after. Nothing should be done to threaten the study’s and as a result Silva is cautious when questioned. A lot of work is done to minimise in order to ensure that the study continues into the future.
A
study members
B
government funding
C
loyalty
D
high costs
E
assessment
F
generalisable results
G
confidentiality
H
barriers to involvement
DOL IELTS Đình Lực
22/10/2026
📖 Bài đọc passage 1
Australia’s Cane Toad Problem
How a toad introduced in Australia to control pests has itself become a pest
In the north of Australia there are many sugar cane plantations, which early in the 20th century were being damaged by a particular pest. This was a species of beetle whose larvae, the infant form of the beetle, live underground in the soil in the sugar cane fields. The sugar cane plants were weakened or died because their roots were eaten by the larvae. This had serious economic consequences for sugar cane farmers. Modern pesticides were not developed until the 1940s, so farmers had to use what was available at the time. Chemicals like arsenic and copper were used, but these were not only expensive but also stayed in the environment and were poisonous to people, plants and animals. It was generally acknowledged by the government, farmers and scientists that cheaper and safer methods of pest control had to be found.
A promising replacement for copper and arsenic was the use of biological control. Farmers already used some forms of biological pest control in the form of predatory and parasitic wasps and flies, insect-eating birds, and plants from different regions or countries to control pests. Common practice was to release these introduced agents into new environments, the expectation being that they would destroy resident pests. Some species of toad already had successful records as agents of biological control in gardens. For example, in 19th-century France toads were sold to gardeners at markets in Paris to eat insect pests in their gardens. In the early 20th century French sugar cane farmers first took giant toads from South America to control pests in their Caribbean sugar cane plantations. Although there is no evidence that these toads did help to control pests, sugar cane scientists then carried some of these toads from Jamaica and Barbados to Puerto Rico and from there to Hawaii.
The idea of biological control of pests was not new to Australia. For example, in 1926 there had been a highly successful prevention of the increase of the exotic prickly-pear cactus by the introduction of a moth from Argentina. This success added strength to the argument that biological control was the answer to the sugar cane industry's pest problems. Accordingly, in the early 1930s a decision was taken to introduce the giant South American toads, which in Australia are now commonly called cane toads, into Australian sugar cane plantations.
In 1935, an Australian entomologist brought 101 cane toads from Hawaii and released them in sugar cane plantations in the north of Australia. However, over the following years it became clear that the cane toads were a failure. There was a fatal flaw in the plan to use them as a form of biological control. This was that earthbound cane toads were expected to eat the mostly flying adult beetles in order to eliminate the soil-dwelling beetle larvae that ate the roots of the cane sugar plants. This, of course, cane toads could not do.
Prior to their introduction in Australia, there had been very few opponents and only one made his views public. He was a retired former Chief Entomologist from the state government of New South Wales named Walter Froggatt. He forecast that cane toads might become as great a pest in Australia as rabbits. However, Froggatt's peers rebuked him and eminent scientists branded his views 'decidedly pessimistic'. It is estimated that today as many as a hundred million cane toads form a toxic infestation which is slowly spreading throughout the land.
Cane toads are large, heavily built amphibians. Average-sized adults are 10–15 cm long and weigh more than a kilo. They have large swellings on each shoulder from which they squirt poison when they are threatened. This venom contains 14 different chemicals, but they do not appear to be harmful to humans as no-one has died in Australia from cane toad poison. Until recently there was no understanding of the toxicity of cane toad poison, but it is now clear that freshwater crocodiles, goannas (large lizards) and dingoes (wild dogs) have died after eating cane toads. Cane toads compete with native Australian fauna for food, and eat the eggs and young of ground-nesting birds. As their numbers increase, they are taking over more and more of the land where native Australian fauna live.
The lesson that can be learned from the introduction of cane toads is important. It is wrong to think that such an awful biological event could not be repeated. In this instance, the catalyst was the overwhelming consensus of support for introducing cane toads to Australia. The error was that there was little or no testing of these biological agents before they were introduced to see what unplanned effects they might have on the environment.
🔥 Đáp án & giải thích 1
1
beetle
Giải thích chi tiết
✅ Step 1: Phân tích câu hỏi
Simplified: The larvae of a type of ___ were a serious pest in sugar cane fields .
Ý câu hỏi: Ấu trùng của một loài ____ là loài gây hại nghiêm trọng trong các cánh đồng mía.
Dự đoán ô trống:
Loại từ: noun số ít, vì sau “a type of” cần một danh từ số ít/chung loại.
Nghĩa/loại thông tin: một loài sinh vật/loài côn trùng có ấu trùng sống trong ruộng mía và gây hại.
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✅ Step 2: Locate bằng chứng
Vì câu hỏi này không có từ khoá đặc biệt như tên riêng hay con số, ta sẽ đọc nhanh đến khi gặp cụm liên quan đến “larvae” và “pest in sugar cane fields”.
Câu liên quan là: “In the north of Australia there are many sugar cane plantations, which early in the 20th century were being damaged by a particular pest. This was a species of beetle ...”
-------
✅ Step 3: Đọc câu bằng chứng theo Linearthinking
Simplified: In the north of Australia there are many sugar cane plantations , which (...) were being damaged by a ... pest .
This was a species of beetle whose larvae (...) live underground (...) .
Lưu ý từ khó:
larvae = ấu trùng
beetle = bọ cánh cứng
→ Chốt ý nghĩa cần điền vào ô trống: Ấu trùng gây hại trong ruộng mía là ấu trùng của một loài beetle.
-------
✅ Step 4: Compare meaning with meaning
Trong bài đọc: loài gây hại cho đồn điền mía là một loài bọ cánh cứng
Trong câu hỏi: cần điền tên loài vật gây hại trong phần nói về pest control
Professor John Lovett from New England University, Australia, describes some of the ways in which plants ensure their own survival
A
A. The general perception of plants is that they are defenceless when faced with threat from animals (including man), insects and other plants. This, however, is not the case. Plants are able to defend themselves against attack from their environment in many ways. There are two major features of plants that ensure their continuation as species. One of these relates to their physical attributes. Spinifex grass, a plant native to Australia, provides a notable example. Adapted to life in the hot, desert inland, spinifex has developed tightly rolled leaves which reduce the effects of drought stress. The hairs, or trichomes, which are found on the inner surface of the rolled-up spinifex leaf are believed to assist in minimising water loss. Trichomes also have defensive roles against predators. Many plants, such as the sunflower, have hairy leaves which are rough to the touch. When the plant is bitten by a grazing animal, the sensation is unpleasant on the tongue and the animal normally moves on to find more palatable food.
B
Some families of plants such as the Solanaceae, which includes the tomato, the potato and other food plants, feature glandular trichomes. In these structures a tiny sac is carried on the hair, which rises from the epidermis, or skin, of the plant. The sac contains chemicals which may perform a range of functions. For example, an insect landing on a tomato leaf and rupturing the sac is exposed to a toxic chemical which will deter it from feeding on that plant in future. In other plants of the same family, the sacs contain a natural adhesive and the unsuspecting insect landing on such a leaf and rupturing a trichome sac is held onto the plant, unable to depart. In the leaves of the nettle plant these trichomes resemble miniature hypodermic syringes. An irritant chemical is stored at the base of the 'syringe'. If an animal touches it, a shot of the chemical is discharged through the 'needle' and into the skin of the animal. The irritation the chemical causes is a deterrent against future threat.
C
The poisons and glues of the Solanaceae and the irritant of the nettle indicate the other major method of plant survival: that some plants use chemicals to protect themselves, sometimes from each other. Chemical interactions that occur between plants are known as 'allelopathy', and in natural plant communities it is one of many factors which determine how plants grow in relation to one another. An example in Australia is the suppression of vegetation growth beneath eucalypt trees, an effect which decreases with increasing distance from the trunk of the tree.
D
The most detailed studies of allelopathy have generally been carried out on agricultural plant communities. In agriculture, allelopathy has been identified particularly with weeds, which compete with desired crop or pasture species, such as wheat, oats and grass, for environmental resources. Competition can be physical, where the growth of one plant maximises the use of water, nutrients and light to the disadvantage of another. Allelopathy, on the other hand, involves plant-produced chemicals which may poison a neighbouring plant. On the whole, weeds are far more physically and chemically aggressive than crop and pasture species. As an example, recent research on the common thorn apple, Datura stramonium, a weed found throughout Australia, has found that two powerful chemicals are released from the seed during the early stages of germination. In fact, it is necessary for the chemicals to be released from the seed coat so that the seed can germinate. Once released, the chemicals then provide a barrier that inhibits the growth of any potential plant competitor near the thorn apple seedling.
E
Allelopathic chemicals function in quite subtle ways. Generally they are active in small quantities, they are effective only with certain other plants, they act by disrupting the plant's natural processes and they have no known residual effects. It has also been found that the activity of these chemicals may be synergistic, that is, two or more such substances may combine to produce an effect that is greater than the effects of the substances acting in isolation. These are the very attributes which are being targeted in the current development of synthetic herbicides*. Allelopathy is not restricted to weeds in agriculture, but allelopathic activity in crop and pasture plants appears to have diminished, possibly because plant breeders may have concentrated on improving aspects of crop quality and quantity rather than aspects of defence against natural enemies.
F
Allelopathic chemicals may be harvested for development as 'natural herbicides', similar to the harvest of pyrethrins from the pyrethrum daisy for use as natural insecticides. Harnessing allelopathy is highly attractive to the farming industry, as at least half of the more than A$200-million annual cost of crop protection in Australia is spent on herbicides. Enhancing allelopathic activity in crop and pasture plants could reduce this enormous bill. Developing and harvesting natural herbicides might also offer real advantages in addressing environmental concerns about the over-use of synthetic chemicals currently used in crop protection. In many parts of the world, communities are showing an increased willingness to pay a premium for products grown with few or no synthetic chemicals, and natural products are becoming increasingly attractive.
🔥 Đáp án & giải thích 2
14
D
Giải thích chi tiết
✅ Step 1: Phân tích câu hỏi (Matching Information)
an example of a plant's use of chemicals in its reproductive process .
Dự đoán thông tin cần tìm (SPECIFY):
Đoạn đúng có thể sẽ nhắc đến:
seed / germination
chemicals được released / produced / used
chemicals giúp cây trong giai đoạn sinh sản hoặc bắt đầu vòng đời mới, chứ không chỉ đơn thuần là defence nói chung
-------
✅ Step 2: Locate bằng chứng
Đoạn D là đoạn khớp nhất.
Câu bằng chứng theo Linearthinking:
As an example, recent research (...) has found that two powerful chemicals are released from the seed during the early stages of germination.
In fact, it is necessary for the chemicals to be released from the seed coat so that the seed can germinate.
-------
✅ Step 3: Đối chiếu paraphrasing
an example ⇔ As an example
a plant's use of chemicals ⇔ two powerful chemicals are released
reproductive process ⇔ the seed / early stages of germination / so that the seed can germinate
=> Khớp rất rõ:đoạn D đưa ra một ví dụ cụ thể về việc cây dùng chemicals trong quá trình germination -> đây chính là một phần của reproductive process.
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❌ Những đáp án “bẫy” dễ nhầm
Bẫy đoạn B: Skim/scan thấy đoạn B có rất nhiều từ về chemicals nên dễ chọn. Nhưng đoạn B chủ yếu nói về:
chemical độc làm côn trùng tránh ăn lá
chất keo giữ côn trùng lại
chất gây kích ứng của nettle
=> Tức là chemicals ở đây dùng cho defence against predators, không liên quan đến reproductive process.
Bẫy đoạn C: Đoạn C cũng có từ khoá chemical interactions và allelopathy. Nhưng đây là nói về cây dùng hoá chất để ảnh hưởng cây khác trong môi trường sống.
=> Vẫn là chemical defence/competition, chưa có ví dụ cụ thể về seed / germination / reproductive process như câu hỏi yêu cầu.
A research project that is now approaching middle age
The New Zealand city of Dunedin in the early 1970s can easily be made to sound idyllic. There was next to no unemployment and people left their doors unlocked at night. New Zealand was then the ninth richest country in the world and many residents believed that, as a place to bring up children, this was a city without rival. However, Phil Silva, an educational psychologist, was not so certain and decided to take a closer look. Silva identified those children born in the year from April 1, 1972 whose mothers were still living in the city three years later. The parents were asked if they would mind bringing their children in for a health and development assessment. Incredibly, no fewer than 91% agreed to help and 1037 three-year-olds completed half a day of tests and experiments. In the process, the Dunedin Multidisciplinary Health and Development Study was born.
There was precious little money at Silva's disposal, so the assessments were done in a church with the help of dozens of volunteers. Each child was assessed against a range of measures such as height, weight, and head circumference. Language skills were assessed and profiles of behaviour were compiled. However, one set of assessments was never going to satisfy Silva's curiosity, so when the children were five, his same team asked the parents to bring the children back for a second study. Of the original 1037 children, 96% came. The data gathered at age three was updated and new measurement criteria - discipline, nutrition, dental health - were introduced.
By 1978, Silva was able to shock the nation with his findings: one in four children had delayed language development; 15% had ear problems; the researchers had identified one child who was blind and another who might have died from undetected skin cancer. New Zealanders, Silva declared, were more diligent about their cars than their children. Cars were required by law to be regularly checked; if children were treated similarly, ideally at behavioural clinics in schools, problems could be picked up in time to prevent lasting damage.
The parents were asked to bring their children back at ages seven, nine and 11 to the old church for further assessments. Crucially for the study's survival, the politicians were finally starting to take note and government funding began to trickle in. By the time the children returned at age 13, the study had taken up residence in an abandoned building tucked behind the dental school. It wouldn't have been the researchers' first choice, and was certainly not grand, but it was at least a site for the long term and its acquisition represented a landmark in the study's development. It was to this building that the participants returned at ages 15, 18, 21, 26 and, most recently, at 32.
Among the most recent findings are that birth complications – a focus of Silva's original research – don't necessarily set children up for problems as they mature in later life, although the amount a newborn infant weighs is associated with IQ. Paediatric textbooks had insisted for years that breast-feeding protected against medical problems like asthma and allergies. The Dunedin study has shown that assumption to be incorrect. Other findings that challenged the received wisdom include the fact that thumb-sucking does no harm; birth order makes no difference to later development; and pre-schoolers whose mothers work are not disadvantaged. Overall, the study has confirmed the notion that broad personality traits are laid down by the age of three. Along the way, the Dunedin researchers have been able to contradict old assumptions and explode medical myths long held by the profession.
The Dunedin study is important not only because of its findings, however. It also provides a model because of the extraordinary commitment of study members. No other longitudinal research project in the world matches its retention rate of 96% at age 32. Silva concedes that luck has a lot to do with this: Dunedin city was, and largely still is, close-knit, homogeneous and devoted to its university and medical school. It is large enough to produce a study population that produces findings that can be generalised to New Zealand and other developed countries, yet small enough that one in every 10 households has had a child or relative in the study.
More important than circumstance, though, was the approach taken by the researchers. Silva recalls that by year 13, participation had dropped off - only 82% came in for assessments. He realised the most important asset they had was the sample group and these people must be nurtured at all costs. He spent many long hours out in the field, finding those participants who had gone adrift and persuading them to come in. Study members are kept up to date with the steady flow of findings to which they have contributed. Privacy is absolutely paramount: Silva won't even say how many of the study members are now in prison: nothing must erode the trust that's been built up over the years.
Today, more than a quarter of the sample live overseas so the study also has its own travel agent, who does her best to accommodate requests to spend Christmas in Dunedin with family. This is just one example of the enormous effort that goes into maintaining contact and removing obstacles to participation. With such diligence and care, researchers hope the Dunedin study will continue for many years, perhaps generations, to come.
🔥 Đáp án & giải thích 3
27
D
Giải thích chi tiết
✅Phân tích câu hỏi:
Câu hỏi hỏi:Tác giả nói gì về Dunedin vào những năm 1970?
Đây là câu hỏi Multiple Choice hỏi ý mà tác giả khẳng định trực tiếp về thành phố này trong giai đoạn đó.
-------
✅Locate thông tin liên quan:
Thông tin nằm ngay đầu đoạn 1.
Cách biết:
Câu hỏi hỏi về Dunedin in the 1970s
Bài mở đầu bằng: “The New Zealand city of Dunedin in the early 1970s…” → đây chính là vùng bằng chứng cần đọc.
-------
✅Đọc thông tin liên quan theo Linearthinking:
(1) The New Zealand city of Dunedin in the early 1970s can easily be made to sound idyllic.
(2) There was next to no unemployment and people left their doors unlocked at night .
(3) many residents believed that, as a place to bring up children, this was a city without rival .
Ý chính của đoạn: Các chi tiết như gần như không có thất nghiệp, không cần khoá cửa, city without rival đều cùng lặp lại một ý chung: Dunedin được người dân nhìn nhận là một nơi rất đáng sống / lý tưởng.
-------
✅Chọn đáp án:
Đáp án đúng là D. The inhabitants thought they lived in a desirable place.
Vì bài nói rõ:
many residents believed
this was a city without rival
as a place to bring up children
Những cụm này cho thấy người dân cho rằng nơi họ sống rất tốt / rất đáng mong muốn / đáng sống.
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❌ Những đáp án còn lại
A. It was the safest city in the country.
Nếu skim/scan, thấy chi tiết “people left their doors unlocked at night” thì rất dễ chọn vì nghe có vẻ an toàn.
Nhưng option này sai vì bài chỉ nói người dân không khoá cửa, chứ không hề khẳng định Dunedin là thành phố an toàn nhất cả nước.
Đây là bẫy kiểu tự suy rộng hơn thông tin trong bài.
B. It was richer than other cities in the country.
Nếu skim thấy “New Zealand was then the ninth richest country in the world” thì có thể nhầm sang ý “Dunedin giàu hơn các thành phố khác”.
Nhưng câu này đang nói về New Zealand là quốc gia giàu, không phải Dunedin giàu hơn các thành phố khác trong nước.
Sai ở chỗ đổi phạm vi thông tin: từ country sang city.
C. Many people were frustrated that they could not find a job.
Option này sai trực tiếp vì bài nói ngược lại:
“There was next to no unemployment” = hầu như không có thất nghiệp.
Nên không thể nói nhiều người không tìm được việc hay frustrated vì chuyện đó.
In the north of Australia there are many sugar cane plantations, which early in the 20th century were being damaged by a particular pest. This was a species of beetle whose larvae, the infant form of the beetle, live underground in the soil in the sugar cane fields. The sugar cane plants were weakened or died because their roots were eaten by the larvae. This had serious economic consequences for sugar cane farmers. Modern pesticides were not developed until the 1940s, so farmers had to use what was available at the time. Chemicals like arsenic and copper were used, but these were not only expensive but also stayed in the environment and were poisonous to people, plants and animals. It was generally acknowledged by the government, farmers and scientists that cheaper and safer methods of pest control had to be found.
A promising replacement for copper and arsenic was the use of biological control. Farmers already used some forms of biological pest control in the form of predatory and parasitic wasps and flies, insect-eating birds, and plants from different regions or countries to control pests. Common practice was to release these introduced agents into new environments, the expectation being that they would destroy resident pests. Some species of toad already had successful records as agents of biological control in gardens. For example, in 19th-century France toads were sold to gardeners at markets in Paris to eat insect pests in their gardens. In the early 20th century French sugar cane farmers first took giant toads from South America to control pests in their Caribbean sugar cane plantations. Although there is no evidence that these toads did help to control pests, sugar cane scientists then carried some of these toads from Jamaica and Barbados to Puerto Rico and from there to Hawaii.
The idea of biological control of pests was not new to Australia. For example, in 1926 there had been a highly successful prevention of the increase of the exotic prickly-pear cactus by the introduction of a moth from Argentina. This success added strength to the argument that biological control was the answer to the sugar cane industry's pest problems. Accordingly, in the early 1930s a decision was taken to introduce the giant South American toads, which in Australia are now commonly called cane toads, into Australian sugar cane plantations.
In 1935, an Australian entomologist brought 101 cane toads from Hawaii and released them in sugar cane plantations in the north of Australia. However, over the following years it became clear that the cane toads were a failure. There was a fatal flaw in the plan to use them as a form of biological control. This was that earthbound cane toads were expected to eat the mostly flying adult beetles in order to eliminate the soil-dwelling beetle larvae that ate the roots of the cane sugar plants. This, of course, cane toads could not do.
Prior to their introduction in Australia, there had been very few opponents and only one made his views public. He was a retired former Chief Entomologist from the state government of New South Wales named Walter Froggatt. He forecast that cane toads might become as great a pest in Australia as rabbits. However, Froggatt's peers rebuked him and eminent scientists branded his views 'decidedly pessimistic'. It is estimated that today as many as a hundred million cane toads form a toxic infestation which is slowly spreading throughout the land.
Cane toads are large, heavily built amphibians. Average-sized adults are 10–15 cm long and weigh more than a kilo. They have large swellings on each shoulder from which they squirt poison when they are threatened. This venom contains 14 different chemicals, but they do not appear to be harmful to humans as no-one has died in Australia from cane toad poison. Until recently there was no understanding of the toxicity of cane toad poison, but it is now clear that freshwater crocodiles, goannas (large lizards) and dingoes (wild dogs) have died after eating cane toads. Cane toads compete with native Australian fauna for food, and eat the eggs and young of ground-nesting birds. As their numbers increase, they are taking over more and more of the land where native Australian fauna live.
The lesson that can be learned from the introduction of cane toads is important. It is wrong to think that such an awful biological event could not be repeated. In this instance, the catalyst was the overwhelming consensus of support for introducing cane toads to Australia. The error was that there was little or no testing of these biological agents before they were introduced to see what unplanned effects they might have on the environment.
This
was a species of beetle
whose larvae (...) live underground (...)
B. Some families of plants such as the Solanaceae, which includes the tomato, the potato and other food plants, feature glandular trichomes. In these structures a tiny sac is carried on the hair, which rises from the epidermis, or skin, of the plant. The sac contains chemicals which may perform a range of functions. For example, an insect landing on a tomato leaf and rupturing the sac is exposed to a toxic chemical which will deter it from feeding on that plant in future. In other plants of the same family, the sacs contain a natural adhesive and the unsuspecting insect landing on such a leaf and rupturing a trichome sac is held onto the plant, unable to depart. In the leaves of the nettle plant these trichomes resemble miniature hypodermic syringes. An irritant chemical is stored at the base of the 'syringe'. If an animal touches it, a shot of the chemical is discharged through the 'needle' and into the skin of the animal. The irritation the chemical causes is a deterrent against future threat.
C. The poisons and glues of the Solanaceae and the irritant of the nettle indicate the other major method of plant survival: that some plants use chemicals to protect themselves, sometimes from each other. Chemical interactions that occur between plants are known as 'allelopathy', and in natural plant communities it is one of many factors which determine how plants grow in relation to one another. An example in Australia is the suppression of vegetation growth beneath eucalypt trees, an effect which decreases with increasing distance from the trunk of the tree.
D. The most detailed studies of allelopathy have generally been carried out on agricultural plant communities. In agriculture, allelopathy has been identified particularly with weeds, which compete with desired crop or pasture species, such as wheat, oats and grass, for environmental resources. Competition can be physical, where the growth of one plant maximises the use of water, nutrients and light to the disadvantage of another. Allelopathy, on the other hand, involves plant-produced chemicals which may poison a neighbouring plant. On the whole, weeds are far more physically and chemically aggressive than crop and pasture species. As an example, recent research on the common thorn apple, Datura stramonium, a weed found throughout Australia, has found that two powerful chemicals are released from the seed during the early stages of germination. In fact, it is necessary for the chemicals to be released from the seed coat so that the seed can germinate. Once released, the chemicals then provide a barrier that inhibits the growth of any potential plant competitor near the thorn apple seedling.
E. Allelopathic chemicals function in quite subtle ways. Generally they are active in small quantities, they are effective only with certain other plants, they act by disrupting the plant's natural processes and they have no known residual effects. It has also been found that the activity of these chemicals may be synergistic, that is, two or more such substances may combine to produce an effect that is greater than the effects of the substances acting in isolation. These are the very attributes which are being targeted in the current development of synthetic herbicides*. Allelopathy is not restricted to weeds in agriculture, but allelopathic activity in crop and pasture plants appears to have diminished, possibly because plant breeders may have concentrated on improving aspects of crop quality and quantity rather than aspects of defence against natural enemies.
F. Allelopathic chemicals may be harvested for development as 'natural herbicides', similar to the harvest of pyrethrins from the pyrethrum daisy for use as natural insecticides. Harnessing allelopathy is highly attractive to the farming industry, as at least half of the more than A$200-million annual cost of crop protection in Australia is spent on herbicides. Enhancing allelopathic activity in crop and pasture plants could reduce this enormous bill. Developing and harvesting natural herbicides might also offer real advantages in addressing environmental concerns about the over-use of synthetic chemicals currently used in crop protection. In many parts of the world, communities are showing an increased willingness to pay a premium for products grown with few or no synthetic chemicals, and natural products are becoming increasingly attractive.
In fact,
it is necessary for the chemicals to be released from the seed coat
so that the seed can germinate
an example
As an example
a plant's use of chemicals
two powerful chemicals are released
reproductive process
the seed
early stages of germination
so that the seed can germinate
The New Zealand city of Dunedin in the early 1970s can easily be made to sound idyllic. There was next to no unemployment and people left their doors unlocked at night. New Zealand was then the ninth richest country in the world and many residents believed that, as a place to bring up children, this was a city without rival. However, Phil Silva, an educational psychologist, was not so certain and decided to take a closer look. Silva identified those children born in the year from April 1, 1972 whose mothers were still living in the city three years later. The parents were asked if they would mind bringing their children in for a health and development assessment. Incredibly, no fewer than 91% agreed to help and 1037 three-year-olds completed half a day of tests and experiments. In the process, the Dunedin Multidisciplinary Health and Development Study was born.
There was precious little money at Silva's disposal, so the assessments were done in a church with the help of dozens of volunteers. Each child was assessed against a range of measures such as height, weight, and head circumference. Language skills were assessed and profiles of behaviour were compiled. However, one set of assessments was never going to satisfy Silva's curiosity, so when the children were five, his same team asked the parents to bring the children back for a second study. Of the original 1037 children, 96% came. The data gathered at age three was updated and new measurement criteria - discipline, nutrition, dental health - were introduced.
By 1978, Silva was able to shock the nation with his findings: one in four children had delayed language development; 15% had ear problems; the researchers had identified one child who was blind and another who might have died from undetected skin cancer. New Zealanders, Silva declared, were more diligent about their cars than their children. Cars were required by law to be regularly checked; if children were treated similarly, ideally at behavioural clinics in schools, problems could be picked up in time to prevent lasting damage.
The parents were asked to bring their children back at ages seven, nine and 11 to the old church for further assessments. Crucially for the study's survival, the politicians were finally starting to take note and government funding began to trickle in. By the time the children returned at age 13, the study had taken up residence in an abandoned building tucked behind the dental school. It wouldn't have been the researchers' first choice, and was certainly not grand, but it was at least a site for the long term and its acquisition represented a landmark in the study's development. It was to this building that the participants returned at ages 15, 18, 21, 26 and, most recently, at 32.
Among the most recent findings are that birth complications – a focus of Silva's original research – don't necessarily set children up for problems as they mature in later life, although the amount a newborn infant weighs is associated with IQ. Paediatric textbooks had insisted for years that breast-feeding protected against medical problems like asthma and allergies. The Dunedin study has shown that assumption to be incorrect. Other findings that challenged the received wisdom include the fact that thumb-sucking does no harm; birth order makes no difference to later development; and pre-schoolers whose mothers work are not disadvantaged. Overall, the study has confirmed the notion that broad personality traits are laid down by the age of three. Along the way, the Dunedin researchers have been able to contradict old assumptions and explode medical myths long held by the profession.
The Dunedin study is important not only because of its findings, however. It also provides a model because of the extraordinary commitment of study members. No other longitudinal research project in the world matches its retention rate of 96% at age 32. Silva concedes that luck has a lot to do with this: Dunedin city was, and largely still is, close-knit, homogeneous and devoted to its university and medical school. It is large enough to produce a study population that produces findings that can be generalised to New Zealand and other developed countries, yet small enough that one in every 10 households has had a child or relative in the study.
More important than circumstance, though, was the approach taken by the researchers. Silva recalls that by year 13, participation had dropped off - only 82% came in for assessments. He realised the most important asset they had was the sample group and these people must be nurtured at all costs. He spent many long hours out in the field, finding those participants who had gone adrift and persuading them to come in. Study members are kept up to date with the steady flow of findings to which they have contributed. Privacy is absolutely paramount: Silva won't even say how many of the study members are now in prison: nothing must erode the trust that's been built up over the years.
Today, more than a quarter of the sample live overseas so the study also has its own travel agent, who does her best to accommodate requests to spend Christmas in Dunedin with family. This is just one example of the enormous effort that goes into maintaining contact and removing obstacles to participation. With such diligence and care, researchers hope the Dunedin study will continue for many years, perhaps generations, to come.
many residents
believed that
as a place to bring up children, this was a city without rival
A. It was the safest city in the country.
Nếu skim/scan, thấy chi tiết “people left their doors unlocked at night” thì rất dễ chọn vì nghe có vẻ an toàn.
Nhưng option này sai vì bài chỉ nói người dân không khoá cửa, chứ không hề khẳng định Dunedin là thành phố an toàn nhất cả nước.
Đây là bẫy kiểu tự suy rộng hơn thông tin trong bài.
B. It was richer than other cities in the country.
Nếu skim thấy “New Zealand was then the ninth richest country in the world” thì có thể nhầm sang ý “Dunedin giàu hơn các thành phố khác”.
Nhưng câu này đang nói về New Zealand là quốc gia giàu, không phải Dunedin giàu hơn các thành phố khác trong nước.
Sai ở chỗ đổi phạm vi thông tin: từ country sang city.
C. Many people were frustrated that they could not find a job.
Option này sai trực tiếp vì bài nói ngược lại:
“There was next to no unemployment” = hầu như không có thất nghiệp.
Nên không thể nói nhiều người không tìm được việc hay frustrated vì chuyện đó.