IELTS Real Reading Test 2025 - Q3 Test 5 with Practice Test, Answers And Explanation
Luyện tập đề IELTS Real Reading Test 2025 - Q3 Test 5 được lấy từ cuốn sách Real Test 2025 - Q3 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 2025 - Q3 Test 5 with Practice Test, Answers And Explanation
Passage
❓ Câu hỏi passage 1
Question 1 - 7
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
1
There is usually little difference in wealth between the various members of a band.
2
In tribes, farmers typically grow a wide range of food plants.
3
A typical tribe has one settlement which is more important than others.
4
In a chiefdom, social status usually depends on the amount of land a person owns.
5
A chiefdom typically contains some workers who are engaged in making goods.
6
An early state may depend on military power to maintain law and order.
7
Bureaucratic officers receive higher salaries than other members.
Question 8 - 13
Answer the questions below.
Choose NO MORE THAN TWO WORDS AND/OR A NUMBER from the passage for each answer.
8
What items do bands produce at work sites?
9
Which way of life, apart from settled farming, may be followed by people in tribes?
10
How were houses arranged in the village of Catalhoyuk?
11
Which items, apart from craft goods, may be given by a chief to members of his chiefdom?
12
What is usually the maximum number of people living in a society which has a chief?
13
Apart from less wealthy inhabitants of cities, which group forms the lowest class in an early state?
Passage
❓ Câu hỏi passage 2
Question 14 - 20
Reading Passage has seven paragraphs A-G
Which paragraph contains the following information?
NB You may use any letter more than once.
14
an example of how farmers in one country are now using satellite data to determine fertilizer use.
15
a reference to climate change and its effects
16
a reference to the effect on the soil of using too much fertiliser
17
an example of information that will be shared between different countries
18
a mention of the country which is the leader in agricultural technology
19
a description of an innovation in satellite imaging which requires further study
20
evidence of the cost effectiveness of using satellite technology in agriculture
Question 21 - 22
Choose TWO letters, A-E.
Which TWO companies obtain information directly from satellites?
A
Sevepl
B
Infoterra
C
Agriculture and AgriFood Canada
D
RapidEye
E
World Agroforestry Centre
Question 23 - 26
Complete the sentences below.
Choose NO MORE THAN TWO WORDS AND/OR A NUMBER from the passage for each answer.
23
Initially, orbiting satellites are used to measure
coming from farmland.
24
believes that confusion about irregular weather will cause more farmers to use satellite technology.
25
As a result of satellite technology, it may become possible to insure against the risk of
.
26
In Africa, much of the soil suffers from the loss of
.
Passage
❓ Câu hỏi passage 3
Question 27 - 31
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
27
Resident killer whales appear to remain with their maternal group for life.
28
Resident killer whales have a more restricted range of calls than transients.
29
There is a vocabulary of sounds which is common to all transient killer whales.
30
Resident killer whales share the dialects of other resident communities living in the same waters.
31
The dialects of transient killer whales remain constant over time.
Question 32 - 34
Choose NO MORE THAN TWO WORDS from the passage for each answer.
It has been observed that resident killer whales invariably live in fixed family groups, known as . Each of these has its own unique set of calls, despite close contact with other family groups. As the same areas of ocean contain many different groups with widely varying dialects, it is clear that these differences could not have emerged as a result of the whales’ .
According to tests conducted by Lance Barrett-Lennard, a calf communicates exclusively with the dialect of the group to which its belongs. Barrett-Lennard also rejects the idea that the call patterns are inherited.
Question 35 - 37
Choose THREE letters, A-F.
Which THREE of the following features of whales are mentioned in the passage?
A
intelligence
B
physical strength
C
sensitivity to sound
D
prolonged life span
E
lengthy period of fertility
F
adaptability to a variety of foods
Question 38 - 40
Reading Passage has eight paragraphs A-H
Which paragraph contains the following information?
Write the correct letter, A-H
38
An example of the kind of information passed by whales to each other.
39
A reference to variations in communication styles between different cultures within one species.
40
Ways in which the skills of whales are favorable for the development of culture.
DOL IELTS Đình Lực
05/05/2026
📖 Bài đọc passage 1
Categorizing societies
When research scholars, including archaeologists and anthropologists, study societies past or present, it can be very useful to have a system of ranking against which to test their ideas. A fourfold categorizing system was developed by the American anthropologist Elman Service; each grouping is associated with certain types of site and settlement. The four types are known as bands, tribes, chiefdoms and early states.
Bands
These are small-scale societies, generally of fewer than 100 people, who live by hunting and gathering, moving seasonally to take advantage of wild (undomesticated) food sources. Most groups who live in this way today, such as the Hadza of Tanzania or the San of southern Africa, would be classified as bands. The members of one band are generally related to each other, either by descent or by marriage. Bands lack formal leaders, so that there are no clear economic differences or other differences in status among the members. Because bands are composed of mobile groups, their sites consist mainly of seasonally occupied camps, and some other sites, such as work sites, where tools are made or other specific activities are carried out. Archaeological sites associated with this type of society may show evidence of insubstantial dwellings, along with the debris of residential occupation. Most sites from the Palaeolithic period (more than 12,000 years ago) seem to be associated with groups of this type.
Tribes
These are generally larger than bands, but rarely number more than a few thousand people, whose diet is mainly based on plants or domestic animals. Typically, these people are settled farmers, but for some groups life is nomadic, with a mobile economy based on herds of animals. Although some tribes have officials, these lack the economic base necessary for effective use of power. The typical settlement pattern for tribes is one of permanent agricultural homesteads or villages. Characteristically, no one settlement dominates any of the others in the region. Instead, the archaeologist often finds evidence of isolated, permanently occupied houses, or permanent villages. These latter may be made up of a collection of free-standing houses like those of the first farmers of the Danube Valley in Europe, or their houses may be grouped together, as in the pueblos of the American southwest, or the early farming village of Catalhoyuk in what is now Turkey.
Chiefdoms
These operate on the principle of ranking – differences in social status between people. Different lineages (groups claiming descent from a common ancestor) are graded on a scale of prestige, and the senior lineage, and hence the society as a whole, is governed by a chief. Prestige and rank are determined by how closely related one is to the chief, and there is no true stratification into classes. The role of the chief is crucial. Often, there is local specialization in craft products such as pottery, cloth and leatherware, and any surplus of these and of foodstuffs is periodically paid to the chief. He uses these to pay his retainers, and may also redistribute them to his subjects as rewards. The chiefdom generally has a centre of power, often with temples, residences of the chief and his retainers, and craft specialists. Chiefdoms vary greatly in size, but the range is generally between 5,000 and 20,000 persons. Chiefdoms give indications that some sites were more important than others, and may have operated as permanent ritual and ceremonial centres, although they were not centres with an established bureaucracy. Examples are Moundville in Alabama USA, or the late Neolithic monuments of Wessex in southern Britain, including the famous ceremonial centre of Stonehenge.
Early states
These preserve many of the features of chiefdoms, but the ruler, perhaps a king or queen, has explicit authority to establish laws and to enforce them by the use of a standing army. The society no longer depends on kin relationships, but is stratified into different classes. Agricultural workers and the poorer urban dwellers make up the base of the pyramid, with the craft specialists above them and the priests and relatives of the ruler higher still. The society is regarded as a territory owned by the ruling lineage, and populated by tenants who have the obligation to pay taxes. The central capital houses the officials of a bureaucratic administration. One of their main functions is to collect revenue (often in the form of taxes and tolls) and distribute it to government, army and craft specialists. Many early states developed complex distribution systems to support these essential services.
Early state societies show a characteristic settlement pattern in which cities play the predominant part. The city is typically a large population centre, often of more than 5,000 people, with major public buildings, and often there is a pronounced settlement hierarchy with the capital city as the major centre, and subsidiary or regional centres as well as local villages. Certainly, it would be wrong to overemphasize the importance of the four types of society given above, or to spend too long agonising as to whether a particular society should be classified in one category or another. However, in seeking to talk about early societies, we must use words and hence concepts to do so. Elman Service's categories provide us with a good framework to organize our thoughts. They should not, however, deflect us from focusing on changes over time in the different institutions of a society, whether in the social sphere, the organisation of the food quest, technology, contact and exchange, or the spiritual life.
🔥 Đáp án & giải thích 1
1
True
Giải thích chi tiết
☺️ Ứng dụng Linearthinking để giải quyết dạng bài True / False / Not Given
Step 01: Read the question to understand (main idea + detail)
Simplified: There is little difference in wealth between various members of a band
-------
Step 02: Locate relevant information
🔍 Từ khoá: "little difference", "members of a band"
→ Dựa vào các từ khoá trên --> Ta tìm được trích dẫn ở đoạn Bands
-------
Step 03: Read relevant information to understand (main + detail)
📌 Trích dẫn: "Bands lack formal leaders, so that there are no clear economic differences or other differences in status among the members." (Đoạn Bands)
Simplified: Bands have no clear economic differences or differences in status among members
Main idea: Thành viên trong band – không có khác biệt đáng kể về kinh tế hay địa vị.
-------
Step 04: Compare meaning with meaning
Trong bài đọc: Các thành viên band không có khác biệt kinh tế rõ rệt.
Trong câu hỏi: Các thành viên band có rất ít khác biệt về sự giàu có.
⇒ ✅ Chọn: TRUE
-------
Giải thích đáp án sai:
FALSE sai: Vì bài đọc khẳng định rõ ràng không có khác biệt kinh tế.
NOT GIVEN sai: Vì bài đọc đã nêu trực tiếp mức độ khác biệt kinh tế giữa các thành viên.
Satellite technology is helping farmers boost crop yields
A
A. For farmers, working out the optimal amount of seed, fertilizer, pesticide and water to scatter on a field can make, or break, the subsequent harvest. Regular laboratory analyses of soil and plant samples from various parts of the field can help - but such expertise is costly, and often unavailable. However, a new and cheaper method of doing this analysis is now on offer. Precise prescriptions for growing crops can be obtained quickly, and less expensively, by calculating the amount of electron-magnetic radiation reflected from agricultural land. The data is collected by orbiting satellites.
B
Examining the wavelength of the radiation that is reflected can reveal, with surprising precision, the properties of the soil, the quantity of crop being grown, and the levels in those crops of chlorophyll, various minerals, moisture and other indicators of their quality. If recent and forecast weather data is added to the mix, detailed maps can be produced indicating exactly how, where and when crops should be grown. The service usually costs less than US $15 per hectare for a handful of readings a year, and can increase yields by as much as 10%.
C
Such precision farming using satellite-based intelligence is a relatively new technique. Even so, it is catching on quickly. Five times a year, for example, a French cereal-growers’ co-operative called Sevepl purchases satellite data and makes it available to its members in the form of maps of their fields, divided into three or four colour-coded zones per hectare. For each zone, one of about 50 fertilizer formulas is recommended. On top of this, if the wheat in the field has already grown quite high early in the season, and heavy showers are expected, an appropriate dose of growth regulator is recommended for each zone (lone, fragile stems break more easily in downpours). Then, farm vehicles equipped with global-positioning system locators automatically mix and apply the prescribed dose to each area.
D
France is the pioneer in this sort of surveillance. More farmland is analysed by satellite there than in any other country, according to Infoterra (a subsidiary of EADS Astrium), the firm that is France’s largest provider of such information, supplying data to companies such as Sevepl. Moreover, Henri Douche, head of Infoterra’s agriculture sales in Toulouse, reckons the amount monitored farmland will increase as weather patterns change and farmers can no longer rely on the past as a guide to the future. When confounded by the yield variations that these new weather patterns will bring, even farmers who are afraid of new technology will sign up, he says.
E
Inexpensive date on the productivity of land is advantageous to governments, too. Areas where fertilisers and pesticides are being applied excessively can be pinpointed, studied and regulated by environmental and land-use agencies. Guy Lafond, an agronomist of Agriculture and Agri-food Canada, a government agency, says the satellite data it purchases is proving useful for the study of fields with declining productivity in the province of Saskatchewan. Overkill with nitrate fertilizers (which are also a source of greenhouse gases) appears partly responsible. And according to RapidEye, a German satellite operator, insurance companies are also studying satellite data with a view to selling insurance policies to governments of famine-prone countries that might be threatened by crop failure.
F
In March, RapidEye began selling data that helps forecast harvest. 'Too often, farmers limit productivity by managing fields uniformly,' says Fredrick Jung-Rothenhausler, head of product development at the firm’s headquarters in Brandenburg an der Havel. ‘Our satellites are the first commercial satellites to include the Red-Edge band of the light spectrum, which is sensitive to changes in chlorophyll content. More research will be necessary to realise the full potential of the Red-Edge band. However, this band can assist in monitoring vegetation health, improving species separation and also help in measuring protein and nitrogen content in biomass.’ The company’s date, which comes from both Europe and the Americas, breaks the field productively down into patches just five metres square.
G
The advantages that satellite technology provides in terms of precision farming do not have to be restricted to rich countries. In Africa, where many soils have become badly depleted of nutrients, better fertilizer management would greatly improve the situation. As a consequence, the charitable trust World Agroforestry Centre, in the city of Nairobi, in Kenya, has begun to build up a catalogue of the radiation patterns derived from around 100,000 samples of African soils. The information is the key to understanding the potential of these soils to be more agriculturally productive. Once passed on to the International Center for Tropical Agriculture, based in Colombia, South America, it is intended that the information will be used to build a database called the ‘Digital Soil Map’. When ready, this will provide farmers with free forecasts, developed with regularly updated satellite imagery, across farmland in a number of countries in Africa. This is information which will almost certainly assist in improving crop yield. For a hunger-ravaged continent, that is good news indeed.
🔥 Đáp án & giải thích 2
14
C
Giải thích chi tiết
☺️ Ứng dụng Linearthinking để giải quyết dạng bài Matching Information
📌 Dạng Matching Information chúng ta nên làm cuối cùng, sau khi đã làm các dạng câu hỏi khác nhé DOLBIES, bởi vì lúc này mình đã đọc và hiểu nội dung của bài rồi, cộng thêm nghệ thuật Specify của Linearthinking → sẽ nhanh chóng tìm được vị trí đáp án hơn!!
-------
Step 01: Read the question to predict
Hiểu câu hỏi: An example of how farmers in one country are now using satellite data to determine fertilizer use
Specify & Predict: Tìm đoạnđưa ra ví dụ thực tế về nông dân ở một quốc gia cụ thể(Ví dụ: Anh, Đức...), mô tả cách nông dân dùng dữ liệu vệ tinh để quyết định lượng / loại phân bón(Ví dụ: chia khu vực, khuyến nghị công thức phân bón,...).
-------
Step 02: Khoanh vùng đoạn văn
🔍 Từ khóa: “example”, “farmers”, “one country”, “satellite data”, “fertilizer use”
→ Dựa vào các từ khoá trên, có thể khoanh vùng được đoạn C vì có xuất hiện các cụm như “French cereal-growers’ co-operative” (hợp tác xã trồng ngũ cốc của Pháp); “maps of their fields, divided into… colour-coded zones” (bản đồ ruộng chia thành các vùng màu); và “one of about 50 fertilizer formulas is recommended” (đề xuất công thức phân bón khác nhau cho từng vùng)
→ Đây là ví dụ cụ thể cho việc nông dân ở một quốc gia sử dụng dữ liệu vệ tinh để quyết định bón phân.
A. Most social scientists stubbornly resist the idea that animals have culture. Even such advanced cetacean mammals as whales and dolphins clearly don’t have art, literature, or architecture. But, patient observation over many years has begun to reveal behaviours that can only have been learnt from other whales. And that, say whale biologists, constitutes culture.
B
B.
So far, humpback and killer whales provide the best evidence of culture in cetaceans, and the song of the male humpback is among the most striking examples. Humpback populations in different oceans sing different songs, but within the same ocean they all stick to the same one. However, during the breeding season the sounds change, as it. appears that females are drawn to novel songs. One male might add an extra set of groans; another might drop a series of grunts. Soon all the other males have altered their own rendition to incorporate the changes until they are once again singing the same song. Since this occurs among thousands of whales spread across a vast part of the planet, the change cannot be in response to any factor in the animals’ environment. The latest version of the song can be learnt only from other whales – almost certainly by imitation.
C
Culture plays an even bigger part in the life of killer whales. Nowhere is this more obvious than along the north-west coast of America, where killer whales are split into two distinct populations – ‘residents’ and ‘transients’. They live in the same stretch of water, but they don’t mingle. In effect, they belong to two quite separate cultures. Residents live in stable groups, or pods, made up of two or three mothers and their offspring - perhaps 20 whales in all. Calves stay with their mothers throughout adulthood, and in many years of observation no one has ever seen a whale switch pods. Transients travel in smaller, more changeable groups of between three and six.
D
One of the most obvious distinctions between the transient and resident societies is the way they impart information. Killer whales detect prey with a range of echo-locating clicks, but converse with a vocabulary of squeaks, whistles and whines. Transients have only a few such calls, and all transient societies share the same ones. Residents have a much more extensive repertoire, and each family group has its own unique and distinctive set of calls. Despite regular interaction between them, each resident pod sticks firmly to its own dialect. Research shows these dialects are maintained for at least 40 years.
E
To qualify as part of killer whale culture, dialects must be learnt from other members of the pod. Animals with different dialects share the same waters, so the variations can’t be a product of the physical environment. ‘And we can throw out the notion that the dialects are inherited,’ says Lance Barrett-Lennard of the University of British Columbia. He has spent the past seven years analyzing DNA from 270 whales. His paternity tests reveal that female killer whales invariably attract mates from outside their own pod – males with a very different dialect. If dialects were programmed by genetics, call patterns from both father and mother would be passed on the calf. ‘A calf uses the calls of its maternal pod very precisely. There’s no input from the father,’ says Barrett-Lennard.
F
The question still remains – is this culture? It is, according to Frans de Waal of Emory University in Atlanta, who argues that culture is just another biological adaptation that has evolved in many creatures. One benefit of viewing culture in this way is that you can start to understand how and why it might have arisen in these creatures. Whales have several biological attributes that give them an advantage in social learning. Apart from their advanced mental abilities, they are adept at recognizing sounds: ideal for communication in the marine environment. Many species spend years rearing their offspring, and live in small, stable, multi-generational societies, a social system that provides ample opportunity for teaching and learning.
G
But why have cetaceans evolved the ability to learn from other group members? Experts in whale biology believe that ecological factors and the need to adapt to sudden changes in the environment played a large part in the emergence of culture. Although the ocean is a relatively stable habitat in many ways, it is highly changeable in one crucial respect – the availability of food. One moment there might be a plentiful supply of fish, the next they’ve disappeared. When that happens, the past experience of the senior members of the group – and the ability to share this knowledge – is a huge asset. The dialects of killer whales allow members of the groups to identify each other, enabling them to share information about food hot spots. Among resident killer whales, it also allows females to avoid inbreeding by picking out a mate with a strange dialect from outside their pods, says Barrett-Lennard.
H
The importance of sharing information seems to have led to biological changes in at least some species of whale. Female killer whales, like humans, are very unusual in that they live up to a quarter of a century after they had their last offspring. This only makes sense if they have something useful to give their descendants. And what whale matriarchs offer is the most important thing of all – cultural knowledge, vital for the group’s survival, passed directly from one generation to the next.
🔥 Đáp án & giải thích 3
27
True
Giải thích chi tiết
☺️ Ứng dụng Linearthinking để giải quyết dạng bài True / False / Not Given
Step 01: Read the question to understand (main idea + detail)
Simplified: Resident killer whales remain with their maternal group for life
-------
Step 02: Locate relevant information
🔍 Từ khóa: “Resident”, “maternal group”, “mothers”, “for life”
=> Dựa vào các từ khoá trên -> Tìm được trích dẫn ở đoạn C.
-------
Step 03: Read relevant information to understand (main + detail)
📌 Trích dẫn: “Calves stay with their mothers throughout adulthood, and in many years of observation no one has ever seen a whale switch pods.”
Simplified: Calves stay with their mothers throughout adulthood ; no whale switches pods
Main idea: Cá voi con ở với mẹ suốt tuổi trưởng thành và không có bằng chứng nào cho thấy chúng đổi đàn.
-------
Step 04: Compare meaning with meaning
Trong bài đọc: Cá voi con ở cùng mẹ suốt đời trưởng thành và không đổi đàn.
Trong câu hỏi: Cá voi sát thủ cư trú dường như ở với nhóm mẹ suốt đời.
→ Hai ý tương đương: cả hai đều khẳng định sự gắn bó lâu dài với nhóm mẹ.
⇒ ✅ Chọn: TRUE
-------
Lưu ý chung:
Nếu đáp án là FALSE: bài đọc phải cho thấy cá voi rời nhóm mẹ hoặc đổi đàn ở một giai đoạn nào đó.
Nếu đáp án là NOT GIVEN: bài đọc sẽ không đề cập đến việc ở cùng mẹ hay đổi đàn.
Bands
These are small-scale societies, generally of fewer than 100 people, who live by hunting and gathering, moving seasonally to take advantage of wild (undomesticated) food sources. Most groups who live in this way today, such as the Hadza of Tanzania or the San of southern Africa, would be classified as bands. The members of one band are generally related to each other, either by descent or by marriage. Bands lack formal leaders, so that there are no clear economic differences or other differences in status among the members. Because bands are composed of mobile groups, their sites consist mainly of seasonally occupied camps, and some other sites, such as work sites, where tools are made or other specific activities are carried out. Archaeological sites associated with this type of society may show evidence of insubstantial dwellings, along with the debris of residential occupation. Most sites from the Palaeolithic period (more than 12,000 years ago) seem to be associated with groups of this type.
Tribes
These are generally larger than bands, but rarely number more than a few thousand people, whose diet is mainly based on plants or domestic animals. Typically, these people are settled farmers, but for some groups life is nomadic, with a mobile economy based on herds of animals. Although some tribes have officials, these lack the economic base necessary for effective use of power. The typical settlement pattern for tribes is one of permanent agricultural homesteads or villages. Characteristically, no one settlement dominates any of the others in the region. Instead, the archaeologist often finds evidence of isolated, permanently occupied houses, or permanent villages. These latter may be made up of a collection of free-standing houses like those of the first farmers of the Danube Valley in Europe, or their houses may be grouped together, as in the pueblos of the American southwest, or the early farming village of Catalhoyuk in what is now Turkey.
Chiefdoms
These operate on the principle of ranking – differences in social status between people. Different lineages (groups claiming descent from a common ancestor) are graded on a scale of prestige, and the senior lineage, and hence the society as a whole, is governed by a chief. Prestige and rank are determined by how closely related one is to the chief, and there is no true stratification into classes. The role of the chief is crucial. Often, there is local specialization in craft products such as pottery, cloth and leatherware, and any surplus of these and of foodstuffs is periodically paid to the chief. He uses these to pay his retainers, and may also redistribute them to his subjects as rewards. The chiefdom generally has a centre of power, often with temples, residences of the chief and his retainers, and craft specialists. Chiefdoms vary greatly in size, but the range is generally between 5,000 and 20,000 persons. Chiefdoms give indications that some sites were more important than others, and may have operated as permanent ritual and ceremonial centres, although they were not centres with an established bureaucracy. Examples are Moundville in Alabama USA, or the late Neolithic monuments of Wessex in southern Britain, including the famous ceremonial centre of Stonehenge.
Early states
These preserve many of the features of chiefdoms, but the ruler, perhaps a king or queen, has explicit authority to establish laws and to enforce them by the use of a standing army. The society no longer depends on kin relationships, but is stratified into different classes. Agricultural workers and the poorer urban dwellers make up the base of the pyramid, with the craft specialists above them and the priests and relatives of the ruler higher still. The society is regarded as a territory owned by the ruling lineage, and populated by tenants who have the obligation to pay taxes. The central capital houses the officials of a bureaucratic administration. One of their main functions is to collect revenue (often in the form of taxes and tolls) and distribute it to government, army and craft specialists. Many early states developed complex distribution systems to support these essential services.
Early state societies show a characteristic settlement pattern in which cities play the predominant part. The city is typically a large population centre, often of more than 5,000 people, with major public buildings, and often there is a pronounced settlement hierarchy with the capital city as the major centre, and subsidiary or regional centres as well as local villages. Certainly, it would be wrong to overemphasize the importance of the four types of society given above, or to spend too long agonising as to whether a particular society should be classified in one category or another. However, in seeking to talk about early societies, we must use words and hence concepts to do so. Elman Service's categories provide us with a good framework to organize our thoughts. They should not, however, deflect us from focusing on changes over time in the different institutions of a society, whether in the social sphere, the organisation of the food quest, technology, contact and exchange, or the spiritual life.
among members
TRUE
B. Examining the wavelength of the radiation that is reflected can reveal, with surprising precision, the properties of the soil, the quantity of crop being grown, and the levels in those crops of chlorophyll, various minerals, moisture and other indicators of their quality. If recent and forecast weather data is added to the mix, detailed maps can be produced indicating exactly how, where and when crops should be grown. The service usually costs less than US $15 per hectare for a handful of readings a year, and can increase yields by as much as 10%.
C. Such precision farming using satellite-based intelligence is a relatively new technique. Even so, it is catching on quickly. Five times a year, for example, a French cereal-growers’ co-operative called Sevepl purchases satellite data and makes it available to its members in the form of maps of their fields, divided into three or four colour-coded zones per hectare. For each zone, one of about 50 fertilizer formulas is recommended. On top of this, if the wheat in the field has already grown quite high early in the season, and heavy showers are expected, an appropriate dose of growth regulator is recommended for each zone (lone, fragile stems break more easily in downpours). Then, farm vehicles equipped with global-positioning system locators automatically mix and apply the prescribed dose to each area.
D. France is the pioneer in this sort of surveillance. More farmland is analysed by satellite there than in any other country, according to Infoterra (a subsidiary of EADS Astrium), the firm that is France’s largest provider of such information, supplying data to companies such as Sevepl. Moreover, Henri Douche, head of Infoterra’s agriculture sales in Toulouse, reckons the amount monitored farmland will increase as weather patterns change and farmers can no longer rely on the past as a guide to the future. When confounded by the yield variations that these new weather patterns will bring, even farmers who are afraid of new technology will sign up, he says.
E. Inexpensive date on the productivity of land is advantageous to governments, too. Areas where fertilisers and pesticides are being applied excessively can be pinpointed, studied and regulated by environmental and land-use agencies. Guy Lafond, an agronomist of Agriculture and Agri-food Canada, a government agency, says the satellite data it purchases is proving useful for the study of fields with declining productivity in the province of Saskatchewan. Overkill with nitrate fertilizers (which are also a source of greenhouse gases) appears partly responsible. And according to RapidEye, a German satellite operator, insurance companies are also studying satellite data with a view to selling insurance policies to governments of famine-prone countries that might be threatened by crop failure.
F. In March, RapidEye began selling data that helps forecast harvest. 'Too often, farmers limit productivity by managing fields uniformly,' says Fredrick Jung-Rothenhausler, head of product development at the firm’s headquarters in Brandenburg an der Havel. ‘Our satellites are the first commercial satellites to include the Red-Edge band of the light spectrum, which is sensitive to changes in chlorophyll content. More research will be necessary to realise the full potential of the Red-Edge band. However, this band can assist in monitoring vegetation health, improving species separation and also help in measuring protein and nitrogen content in biomass.’ The company’s date, which comes from both Europe and the Americas, breaks the field productively down into patches just five metres square.
G. The advantages that satellite technology provides in terms of precision farming do not have to be restricted to rich countries. In Africa, where many soils have become badly depleted of nutrients, better fertilizer management would greatly improve the situation. As a consequence, the charitable trust World Agroforestry Centre, in the city of Nairobi, in Kenya, has begun to build up a catalogue of the radiation patterns derived from around 100,000 samples of African soils. The information is the key to understanding the potential of these soils to be more agriculturally productive. Once passed on to the International Center for Tropical Agriculture, based in Colombia, South America, it is intended that the information will be used to build a database called the ‘Digital Soil Map’. When ready, this will provide farmers with free forecasts, developed with regularly updated satellite imagery, across farmland in a number of countries in Africa. This is information which will almost certainly assist in improving crop yield. For a hunger-ravaged continent, that is good news indeed.
to determine fertilizer use
Specify & Predict: Tìm đoạnđưa ra ví dụ thực tế về nông dân ở một quốc gia cụ thể(Ví dụ: Anh, Đức...), mô tả cách nông dân dùng dữ liệu vệ tinh để quyết định lượng / loại phân bón(Ví dụ: chia khu vực, khuyến nghị công thức phân bón,...).
So far, humpback and killer whales provide the best evidence of culture in cetaceans, and the song of the male humpback is among the most striking examples. Humpback populations in different oceans sing different songs, but within the same ocean they all stick to the same one. However, during the breeding season the sounds change, as it. appears that females are drawn to novel songs. One male might add an extra set of groans; another might drop a series of grunts. Soon all the other males have altered their own rendition to incorporate the changes until they are once again singing the same song. Since this occurs among thousands of whales spread across a vast part of the planet, the change cannot be in response to any factor in the animals’ environment. The latest version of the song can be learnt only from other whales – almost certainly by imitation.
C. Culture plays an even bigger part in the life of killer whales. Nowhere is this more obvious than along the north-west coast of America, where killer whales are split into two distinct populations – ‘residents’ and ‘transients’. They live in the same stretch of water, but they don’t mingle. In effect, they belong to two quite separate cultures. Residents live in stable groups, or pods, made up of two or three mothers and their offspring - perhaps 20 whales in all. Calves stay with their mothers throughout adulthood, and in many years of observation no one has ever seen a whale switch pods. Transients travel in smaller, more changeable groups of between three and six.
D. One of the most obvious distinctions between the transient and resident societies is the way they impart information. Killer whales detect prey with a range of echo-locating clicks, but converse with a vocabulary of squeaks, whistles and whines. Transients have only a few such calls, and all transient societies share the same ones. Residents have a much more extensive repertoire, and each family group has its own unique and distinctive set of calls. Despite regular interaction between them, each resident pod sticks firmly to its own dialect. Research shows these dialects are maintained for at least 40 years.
E. To qualify as part of killer whale culture, dialects must be learnt from other members of the pod. Animals with different dialects share the same waters, so the variations can’t be a product of the physical environment. ‘And we can throw out the notion that the dialects are inherited,’ says Lance Barrett-Lennard of the University of British Columbia. He has spent the past seven years analyzing DNA from 270 whales. His paternity tests reveal that female killer whales invariably attract mates from outside their own pod – males with a very different dialect. If dialects were programmed by genetics, call patterns from both father and mother would be passed on the calf. ‘A calf uses the calls of its maternal pod very precisely. There’s no input from the father,’ says Barrett-Lennard.
F. The question still remains – is this culture? It is, according to Frans de Waal of Emory University in Atlanta, who argues that culture is just another biological adaptation that has evolved in many creatures. One benefit of viewing culture in this way is that you can start to understand how and why it might have arisen in these creatures. Whales have several biological attributes that give them an advantage in social learning. Apart from their advanced mental abilities, they are adept at recognizing sounds: ideal for communication in the marine environment. Many species spend years rearing their offspring, and live in small, stable, multi-generational societies, a social system that provides ample opportunity for teaching and learning.
G. But why have cetaceans evolved the ability to learn from other group members? Experts in whale biology believe that ecological factors and the need to adapt to sudden changes in the environment played a large part in the emergence of culture. Although the ocean is a relatively stable habitat in many ways, it is highly changeable in one crucial respect – the availability of food. One moment there might be a plentiful supply of fish, the next they’ve disappeared. When that happens, the past experience of the senior members of the group – and the ability to share this knowledge – is a huge asset. The dialects of killer whales allow members of the groups to identify each other, enabling them to share information about food hot spots. Among resident killer whales, it also allows females to avoid inbreeding by picking out a mate with a strange dialect from outside their pods, says Barrett-Lennard.
H. The importance of sharing information seems to have led to biological changes in at least some species of whale. Female killer whales, like humans, are very unusual in that they live up to a quarter of a century after they had their last offspring. This only makes sense if they have something useful to give their descendants. And what whale matriarchs offer is the most important thing of all – cultural knowledge, vital for the group’s survival, passed directly from one generation to the next.
Main idea: Cá voi con ở với mẹ suốt tuổi trưởng thành và không có bằng chứng nào cho thấy chúng đổi đàn.
