－HowoftendoIneedtofeedthebird?－They

问题详情：

－How often do I need to feed the bird?

－They ________ food every day，or they will be hungry.

A. must give        B. mustn't give

C. must be given    D. mustn't be give

【回答】

C

知识点：动词语态

题型：选择题