1. major adj. 较大的，较多的，主要的，主修的（minor 较小的，较少的，次要的）
The major part 主要部分 major subjects 主修课程 major party 大党
vi. 主修，专攻 n.
He majors in chemistry. 他主修化学。
2. prevent vt. 阻止，防止，预防
It is the job of the police to prevent crime. 防止犯罪是警察的职责。
What / Who prevented him from going / prevented his going / prevented him going?
We were prevented / stopped / kept by heavy smog from seeing anything.
