1. A 主干 What matters most to us is to keep fit.
2. D 固定句型
3. C prevent from 固定短语, being polluted 被动语态
4. B crash into 撞上……
1.A what
2.D that
3.C
4.B
1、A 做主语。,he often says是插入语
2、 D主语从句中的用法。
3、Cprevent sb from doing sth,但这里不是人,是物,是阻止被污染,所以用被动语态。
4、B crash into碰撞 如: The motorcycle crashed into the fence.
摩托车猛地撞在围栏上。