Passage Fifteen
There are two factors which determine an individual's intelligence. The first is the sort of brain he is born 1 . Human brains differ considerably, some being more capable than others. 2 no matter how good a brain he has to begin with, an individual will have a low order of intelligence unless he has opportunities to learn. So the second factor is what 3 to the individual-the sort of environment in which he is brought up. If an individual is handicapped(受阻碍) 4 , it is likely that his brain will fail to develop and he will never attain the level of intelligence of which he is 5 .
The importance of environment in determining an individual's intelligence can be 6 by the case history of the identical twins, Peter and John. When the twins were three months old, their parents died, and they were placed in separate foster(寄养)homes, Peter was reared by parents of low intelligence in an 7 community with poor educational opportunities. John, however, was educated in the home of welltodo parents who had been to college. This environmental 8 continued until the twins were in their late teens, when they were given tests to 9 their intelligence. John's I.Q.(智商)was 125, twentyfive points higher than the 10 and fully forty points higher than his identical brother.
1.［A］ for ［B］ by ［C］ with ［D］ in 2.［A］ But ［B］ For ［C］ Still ［D］ And 3.［A］ refers ［B］ applies ［C］ happens ［D］ concerns 4.［A］ relatively ［B］ intelligently［C］ regularly ［D］ environmentally 5.［A］ able ［B］ capable ［C］ available ［D］ acceptable 6.［A］ demonstrated［B］ denied ［C］ neglected ［D］ ignored 7.［A］ omitted ［B］ isolated ［C］ enclosed ［D］ occupied 8.［A］ exception ［B］ division ［C］ difference［D］ alteration 9.［A］ estimate ［B］ count ［C］ decide ［D］ measure 10.［A］ average ［B］ common ［C］ usual ［D］ ordinary
