What happens to the individual— the sort of environment in which he is brought up is one of factors which determine an individual's intelligence. If an individual is handicapped(不利) environmentally, it is likely that his brain will1. fail to develop and he will never 2. attain the level of intelligence of which he is capable. The importance of 3.environment in determining an individual's intelligence can be 4.demonstrated by the case history of the 5.
