Question

【题目】Some rules _________ to stop people from polluting the environment.

A.must make B.must be made C.must made D.be made

Answer 1

【答案】B

【解析】rules和make之间是被动关系，由此排除A和C；分析语境可知此处指的是“一些条例必须制定来防止人们污染环境”，“必须……”用must，不可省略。