【题目】空气污染变得越来越严重。

【题目】永远不要忘记感恩你周边的人。

【题目】近些年，我们学校发生了很大变化。

【题目】当我到家时，我意识到我的英语书忘在学校了。

【题目】My best friend, Tom gave us some most useful ____________ (suggest).

【题目】I’m sure most of the students will feel _______ (thank) to their teachers after they leave school.

【题目】Something must _________ (do )to stop the sale of shark fins.

【题目】The plan is not a new _________(discover), it’s been known for years.

【题目】I’m afraid he can’t afford ________ (wait) to go shopping.

【题目】Their house is very similar to __________ (our), but theirs is much smaller.