问题补充:
— Must I return the book this week?
— No, you . You can _it for 20 days.
A. mustn : keep
B. needn ; borrow
C. needn ; keep
D. mustn ; borrow
答案:
A. mustn : keep
B. needn ; borrow
(答案→)C. needn ; keep
D. mustn ; borrow
解析:must回答与延续性动词的用法。Must开头的一般疑问句的否定回答用“……needn’t”, 由答语for短语指一段时间,故用延续性动词,borrow为短暂性动词,要换成延续性动词keep。