The reading room needs but it’ll have to wait until Saturday or Sunday.A. to cleanB. bei

问题补充：

The reading room needs , but it’ll have to wait until Saturday or Sunday.

A. to clean

B. being cleaned

C. be cleaned

D. cleaning

答案：

A. to clean

B. being cleaned

C. be cleaned

D. cleaning

解析：考查动名词做宾语：need doing=need to be done需要被…，句意：阅览室需要被打扫干净，但还得等到星期六或星期天。选D。