单选题
Are some people born clever and others born stupid? Or is intelligence developed by our environment and our experiences? Strangely【C1】______, the answer to both these questions is yes. To some extent our intelligence is given us at birth, and no amount of special education can make a genius【C2】______a child born with low intelligence. On the other hand, a child who lives in boring environment will develop his intelligence less than the one who lives in rich and varied surroundings. Thus the【C3】______of a person" s intelligence are fixed at birth, but whether or not he reaches those limits will depend on his【C4】______This view, not held by most experts, can be supported in a number of ways. It is easy to show that intelligence is to some extent【C5】______we are born with. The closer the blood relationship between two people, the closer they are likely to be in intelligence. Thus if we take two unrelated people【C6】______, it is likely that their degrees of intelligence will be completely different. If on the other hand we take two identical twins they will likely be as intelligent as each other. Relations like brothers and sisters, parents and children, usually have【C7】______intelligence and this clearly suggests that intelligence depends on birth. 【C8】______now that we take 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 developing, and this indicates that environment【C9】______birth plays a part. This conclusion is also suggested by the【C10】______that people who live in close contact with each other,but who are not related at all, are likely to have similar degrees of intelligence.