完形填空

　　Are some people born clever, and others born stupid? Or is intelligence (智力) developed by our environment and our experiences? 1 enough, the answer to both these questions is 2 . To some degree our intelligence is given us 3 , and no amount of special education can 4 a genius out of a child born 5 low intelligence. On the other hand, a child who lives in a (n) 6 environment will develop his intelligence less than 7 who lives in rich and varied 8 . Thus the limits of a person's intelligence are fixed at birth, 9 whether or not he reaches those limits will 10 on his environment. This view, now held 11 most experts, can be supported in a number of ways.

　　It is easy to show 12 intelligence is to some degree something we are born with. 13 the blood relationship between two people, the closer they are 14 to be in intelligence. Thus if we take two unrelated people 15 from the population, it is likely that their degrees of 16 wilt be completely different. If on the other hand we 17 two identical twins, they will very likely be 18 intelligent as each other. Relations 19 brothers and sisters, parents and children, usually have similar intelligence, and this clearly suggests that intelligence 20 birth.

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