— What would you like _______ your afternoon tea？

— Just a cup of coffee _______ some sugar and milk.

A．of; with

B．of; without

C．for; with

D．for; without

电场中A、B两点间的电势差为U，一个静止于A点、电量为q的正点电荷，在电场力的作用下从A点移动到B点。电场力所做的功等于（　）

A.U                 B.U/q             C.q/U               D.qU