please ( ) your hands before ( ) lunch

问题描述:

please ( ) your hands before ( ) lunch
A.wash have B.washing having C.wash having D.wash have
选哪一个 为什莫

C
第一空,此处要填动原, 因为没主语, 前面又有please, 即为祈使句.
第二空,before为介词,介词后动词要加ing