Passage Three
Are some people born clever, and others born stupid?Or is the development of intelligence dependent on environment and experience?Strangely enough, the answer to both questions is yes. To some extent, our intelligence is given us at birth. On the other hand, [33]a child who lives in a boring environment will develop his intelligence less than one who lives in rich and varied surroundings.
It is easy to show that intelligence is something we are born with.The closer the blood relationship between two people, the closer they are likely to be in intelligence. Therefore if we take two unrelated people at random from the population, it is likely that their degree of intelligence will be completely different.If we take two identical twins, they will very likely be as intelligent as each other. [34]Relations like brothers and sisters, parents and children, usually have similar intelligence, and this clearly suggests that intelligence depends on birth.
Imagine that we take two identical twins and put them in different environments. We might send one, for example, to a university and the other to a factory where the work is boring. We would soon find differences in intelligence development, and this indicates that environment as well as birth plays a part. This conclusion is also suggested by the fact that [35]people who live in close contact with each other, but who are not related at all, are likely to have a similar degree of intelligence.

Questions 33 to 35 are based on the passage you have just heard.
33. What degree of intelligence might a child have, if he lives in a rich and varied environment?
正确答案：A
解析：选项A、B、C中的surroundings, environment和circumstance都有“环境”的意思，所以原文提到environment的时候就要留心。原文说在单调环境下生活的孩子比生活在丰富多彩环境下的孩子智力发展得少，故A正确，A中的dull是对原文中boring的同义替换。
34. Why does the speaker say that intelligence depends on birth?
正确答案：C
解析：原文说兄弟姐妹和父母孩子这类关系的人通常来说智力水平相似，这说明智力依赖血统，故选C。
35. What do we learn about unrelated people who live in close contact according to the passage?
正确答案：D
解析：原文说生活中相互亲密接触、但是并没有任何关系的人，很可能智力水平相似，故D正确。四个选项中只有D含有原文中出现频率最高的词intelligence，仅凭这一点也可以猜测它是正确答案。