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

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

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

Please (wash) your hands before (having) lunch
整句是祈使句，主句动词用原形
before是介绍，后跟名词或动词ing形式