英语翻译
There are two factors that determine an individual’s intelligence (一个人的智商).The first is the sort of brain he is born with.Human brains differ considerably(相当地),some being more capable (有能力的) than others.But 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 happens to the individual — the sort of environment (surroundings) in which he is brought up.
只需要翻译这句：“So the second factor is what happens to the individual — the sort of environment in which he is brought up.”