Customers are asked to make sure that they the right change (零钱) before leaving the shop.

问题补充：

Customers are asked to make sure that they the right change (零钱) before leaving the shop.

A. will give

B. will be given

C. have given

D. have been given

答案：

A. will give

B. will be given

C. have given

(答案→)D. have been given

解析：考查时态。句意：在离开商店之前，要求顾客确信他们给找给了正确的零钱。结合语境可知下文描述的是某时前完成的动作，故用完成时态。They是动作对象，故用被动语态。选D。