Are some people born clever, and others born stupid？ Or is intelligence level opened by ou

r environment and our experience？【C1】______, the answer to these questions is yes.【C2】______some extent our intelligence is given us at birth, and no amount of special education can make a genius【C3】______a child born with【C4】______ntelligence. On the other hand, a child who lives in a【C5】______environment will develop his intelligence less than one who lives in rich and varied surroundings.【C6】______the limits of a persons intelligence are fixed at birth. Whether or not he reaches those【C7】______will depend on his environment. This view, now【C8】______by most experts, can be supported in a number of ways. It is easy to show that intelligence is to some extent something we are born【C9】______. The closer the blood relationship between two people, the closer they are likely to be in intelligence. Thus if we take two unrelated people【C10】______from the population, it is likely that their degree of intelligence will be completely【C11】______. If, on the other hand, we take two【C12】______twins, they will very likely be as intelligent as each other.【C13】______like brothers and sisters, parents and children, usually have【C14】______intelligence, and this clearly suggests that intelligence depends on birth. Imagine now that we take two identical twins and put them in different environments. We might send one, for example, to a university and【C15】______to a factory where the work is boring. We would soon find differences【C16】______intelligence developing, and this indicates that environment【C17】______birth plays a part. This【C18】______is also suggested by the fact that people who live in close【C19】______with each other, but who are not【C20】______at all are likely to have similar degree of intelligence.

【C1】

A．Obviously enough

B．Obvious

C．Strangely enough

D．Strange enough