［動詞的語態(tài)］need/want/require/worth
當 need， want， require， be worth后面接doing時，表示的是被動意義。例如：
Your hair wants cutting. 你的頭發(fā)該理了。
The floor requires washing. 地板需要沖洗。
典型例題
The library needs___， but it'll have to wait until Sunday.
A. cleaning B. be cleaned C. clean D. being cleaned
答案A. need (實意) +n /to do，need (情態(tài))+ do，當為被動語態(tài)時，還可need + doing. 本題考最后一種用法，選A.如有to be cleaned 則也為正確答案。
