---You must    what I have done for you before you leave.

问题描述:

---You must    what I have done for you before you leave.
---Well,how much does it Is 100 dollars enough?
 A.pay for,cost   B.pay,spend   C.spend,pay for   D.pay,cost

D
pay for 为.付款.cost的意思是,某物花费.主语是物.spend的意思是,花费...干某事,主语是人.