Question

The classroom is so dirty that it needs ________ badly.

1. A.
   clean
2. B.
   to clean
3. C.
   being cleaned
4. D.
   cleaning

Answer 1

D
解析：
sth. needs/wants/requires doing/to be done为固定句式，表示“某物需要……”，主语sth与宾语doing/to be done是逻辑上的动宾关系。