---With 4G mobile phones people can even see each other as they talk----Really? Would

问题补充：

---With 4G mobile phones, people can even see each other as they talk.

----Really? Would you show me it, please?

A. how to use

B. when to use

C. where to use

D. what to use

答案：

(答案→)A. how to use

B. when to use

C. where to use

D. what to use

解析：句意：——使用4G手机，人们甚至可以看到他们彼此交谈。——真的吗？请你可以给我展示一下怎么使用它好吗？根据句意可知是怎样使用4G手机，故选A。