Question

【题目】We must__________ rubbish. We should__________ the environment clean.

A.not to leave, to keepB.not leave, keep

C.not leave, to keepD.not to leave, keep

Answer 1

【答案】B

【解析】

句意：我们不能留下垃圾。我们应该保持环境清洁。

根据句意理解可知，must是情态动词，后面要接动词原形，否定直接在must后面加not，然后接动词原形，而第二空中should也是情态动词，后面要接动词原形，所以综合之后本题应该选择B答案。