The library needs but it will have to wait until Sunday.A. cleaningB. be cleanedC. clean

问题补充：

The library needs , but it will have to wait until Sunday.

A. cleaning

B. be cleaned

C. clean

D. being cleaned

答案：

(答案→)A. cleaning

B. be cleaned

C. clean

D. being cleaned

解析： need等词表示需要时后面一般跟懂名词的主动形式表示被动意思。