Customers are asked to make sure that they the right change before leaving the shop.A. wi

问题补充：

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

A. will give

B. have been given

C. have given

D. will be given

答案：

A. will give

(答案→)B. have been given

C. have given

D. will be given

解析：考查时态，由后面的句子before leaving the shop.可以知道动作已经完成，所以用完成时，they和动词give是动宾关系，所以用被动式，句子意思“消费者被要求离开商店之前做出正确改变”， make sure固定词组“确保”，后面跟从句，所以选B