物作主语时：
sth. want doing ,这时候的want,意思是“必须,应该”,相当于need.这里的doing有被动的意思,相当于to be done.
如,Your hands want/need washing. 你的手应该洗洗.
因此,Your hair wants cutting或 Your hair wants to be cut 都可以 物作主语时：
sth. want doing ,这时候的want,意思是“必须,应该”,相当于need.这里的doing有被动的意思,相当于to be done.
如,Your hands want/need washing. 你的手应该洗洗.
因此,Your hair wants cutting或 Your hair wants to be cut 都可以