Question

【题目】To make our city more beautiful, rubbish _________ into the river.
A.needn't be thrown
B.can't thrown
C.mustn't be thrown
D.may not thrown

Answer 1

【答案】C
【解析】为了使我们的城市更美丽，禁止往河里扔垃圾。根据语境，本句的主语是动作的承受者，应用被动语态。另外，表示禁止、不允许应用mustn’t。故选C。