Question

【题目】—Can you stay for lunch?

—Sorry, I __________. I have to go back home now.

A.can'tB.needn'tC.mustn'tD.shouldn't

Answer 1

【答案】A

【解析】

句意：——你能留下来吃午饭吗？——对不起，我不能。我现在必须回家了。

can't不能；needn't不必； mustn't 禁止；shouldn't不应该。根据“Sorry及下文“I have to go back home now.”可知，这里是不能，用can't，根据题意，故选A。