Questions 18 to 20 are based on the following passage.

(18) There are two factors which determine an individual’s intelligence. The first is the sort of brain he is born with. Human brains differ considerably, some being more capable than others. But no matter how good a brain he has to begin with，an individual will have a low order of intelligence unless he has opportunities to learn. (18) So the second factor is what happens to the individual and the sort of environment in which he is reared. If an individual is handicapped environmentally, it is likely that his brain will fail to develop. The importance of environment in determining an individual’s intelligence can be demonstrated by the case of the identical twins. Peter and Mark. Being identical, the twins had identical brains at birth, and their growth processes were the same. When the twins were three months old，their parents died, and they were placed in separate foster homes. Peter was reared by parents of low intelligence in an isolated community with poor educational opportunities. Mark was reared in the home of well- to-do parents who had been to college. He was sent to good schools, and given every opportunity to be stimulated intellectually. This environmental difference continued until the twins were in their late teens, when they were given tests to measure their intelligence. (19) Mark’s I. Q. was 125，twenty-five points higher than the average and fully forty points higher than his identical brother.

 

题目

Passage 4

Questions 18 to 20 are based on the following passage. At the end of the passage, you will be given 15 seconds to answer the questions.

Now, listen to the passage.

18. The best statement of the main idea of this passage is that____ .

A. human brains differ considerably

B. the brain a person is born with is important in determining his intelligence

C. environment is crucial in determining a person's intelligence

D. persons having identical brains will have roughly the same intelligence

19. According to the passage, the average I.Q. is ____?

A. 85 B. 100 C.110 D. 125

20. This passage suggests that an individual’s I. Q. ____?

A. can be predicted at birth

B. stays the same throughout his life

C. is determined by his childhood

D. can be increased by education

 

答案解析

18. C主旨题。细听本文可获得如下信息：决定人的智力高低有两个因素，分别是与 生俱来的大脑和后天的成长环境。相比之下，后者更为重要。读选项，只有C符合 题意，为正确答案。

19. B细节题。在后来对双胞胎智商的测试中，Mark的智商为125，比平均值和同胞 兄弟分别高25点和40点，故推之平均智商为100，答案为B。

20. D推理题。通过双胞胎实验证明，不同教育和成长环境下的孪生兄弟智力发展也 不相同，良好的教育背景会促进智力的发展。因此可以判断D为正确答案。