1.illegal immigration 非法移民

例句：Action against illegal immigration is one of the Force's top priorities.

反非法入境是警方最优先处理的工作之一.

2.a series of 一系列

例句：Boom! Boom! Boom! A series of explosions shook the valley.

轰!轰!轰! 一连串爆破声震撼山谷。

3.go back 返回

例句：Someone is waiting for you at home. You'd better go back right now.

你回去吧， 家里有人找你。

4.presidential candidate 总统候选人

例句：The presidential candidate backwatered on several promises when he got into office.

总统候选人就职后背弃了好几项承诺。