You should spend about 20 minutes on Questions 27-40, which are based on Reading Passage 3 below. Have teenagers always existed?

单选题 In the first paragraph, why does the writer say This is not merely an academic debate'?

A、 Anthropologists' theories need to be backed up by practical research.
B、 There have been some important misunderstandings among anthropologists.
C、 The attitudes of anthropologists towards adolescence are changing.
D、 The work of anthropologists could inform our understanding of modern adolescence.

【正确答案】 D

【答案解析】解析：The 'academic debate' refers back to the discussion between 'anthropologists' but the text goes on to say 'we have very little idea why' humans have adolescence and that studies 'could help us understand its purpose'(i.e. have a practical use today). Distraction A and C: These both refer to information in the text but they don't answer the question; B: There is no mention of a 'misunderstanding' between anthropologists in the first paragraph.

单选题 What was Susan Anton's opinion of the Turkana boy?

A、 He would have experienced an adolescent phase had he lived.
B、 His skull showed he had already reached adulthood.
C、 His skeleton and teeth could not be compared to those from a more modern age.
D、 He must have grown much faster than others alive at the time.

【正确答案】 A

【答案解析】解析：The fourth paragraph says 'She thinks that Homo erectus had already developed ... adolescent spurt' and 'Turkana boy was just about to enter it'. Distraction B: This is denied in the text: '... a rounded skull, and needs more growth to reach the adult shape'; C: His skeleton and teeth showed similar discrepancies to those from the 18th and 19th centuries(so they were compared with a 'more modern age1); D: He was slightly tall for his apparent age but the text doesn't compare him with others alive at the time - they might all have been this tall.

单选题 What point does Steven Leigh make?

A、 Different parts of the human skeleton develop at different speeds.
B、 The growth period of many apes is confined to times when there is enough food.
C、 Humans have different rates of development from each other depending on living conditions.
D、 The growth phase in most apes lasts longer if more food is available.

【正确答案】 B

【答案解析】解析：In the fifth paragraph Steven Leigh says 'many apes have growth spurts ... to coincide with the seasons when food is plentiful, they minimise the risk of being without adequate food supplies while growing'. He says that many apes have growth spurts in different parts of their bodies which mature at different times. He attributes this to the fact that they only grow at times when food is plentiful. Distraction A: 'the whole[human]skeleton is involved'(different parts don't grow at different speeds); C: There is no mention of the difference between humans, only between humans and apes; D: He says that the growth spurts and the periods when food is plentiful are short. He doesn't suggest there are longer periods of growth when there is more food.

单选题 What can we learn from a mammal's teeth?

A、 A poor diet will cause them to grow more slowly.
B、 They are a better indication of lifestyle than a skeleton.
C、 Their growing period is difficult to predict accurately.
D、 Their speed of growth is directly related to the body's speed of development.

【正确答案】 D

【答案解析】解析：'The rate at which teeth develop is closely related to how fast the brain grows and the age you mature'. Distraction A: The text contradicts this: 'their growth is less related to ... nutrition than is the growth of the skeleton'; B: The text suggests the opposite as 'their growth is less related to the environment and nutrition than is the growth of the skeleton'(they are good indicators of 'life history', not 'lifestyle'); C: The text suggests the opposite: 'Every nine days or so ... how long the crown of a tooth took to form'.