题干
A: Mum, may I go out to play football for an hour? B: No, you_ . The air outside is not very clean.
A：can't
B：needn't
C：couldn't
答案(点此获取答案解析）
A
A: Mum, may I go out to play football for an hour? B: No, you_ . The air outside is not very clean.
A：can't
B：needn't
C：couldn't
