Are some people born clever, and others born stupid? Or is intelligence developed by our environment and our experiences? Strangely enough, the answer to both these questions is yes．To some degree our intelligence is given to us at birth, and no amount of special education can make a genius （天才） out of a child born with low intelligence．On the other hand, a child who lives in a boring environment will develop his intelligence less than one who lives in rich and varied surroundings．Thus the limits of a person’s intelligence are fixed at birth, but whether or not he reaches those limits will depend on his environment．This view, now held by most experts can be supported in a number of ways．
It is easy to say that intelligence is to some degree something 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 at random from the population, it is likely that their degrees of intelligence will be completely different．If on the other hand we take two identical twins, they will very likely be as intelligent as each other．Relations like brothers and sisters, parents and children, usually have similar intelligence, and this clearly suggests that intelligence depends on birth．
Imagine that now 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 developing, and this indicates that environment as well as birth plays a part．This conclusion is also suggested by the fact 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．
By using the example that two people closer in blood relationship are closer in intelligence, the writer wants to prove _________．

A．intelligence is given at birth

B．intelligence can be developed by environment

C．intelligence can be developed by experience

D．education plays an important part in the development of education

A child who lives in rich and varied surroundings turns out higher in intelligence because ________．

A．his family is rich and therefore can afford to develop his intelligence

B．he can break the limits of intelligence fixed at birth

C．his family is rich and provides him with various healthy food

D．these surroundings are likely to help him reach the limits of their intelligence

The writer of this article believes that _________．

A．the development of one’s intelligence is determined by many things working together

B．environment plays the most important role in the development of intelligence

C．education plays the most important role in the development of intelligence

D．birth plays the most important role in the development of intelligence

The best title for this passage might be __________．

A．The Answer to a Question	B．Birth and Environment
C．Intelligence	D．Intelligence and Education