问题补充：
—We can use QQ to talk with each other online.
—Really? Could you show me it?
A. what to do
B. how to do
C. when to do
D. why to do
答案：
A. what to do
(答案→)B. how to do
C. when to do
D. why to do
解析：根据语境可知此题考查的是疑问词+动词不定式的基本用法。此句的含义是你能告诉我怎样操作吗?询问的是方式，故用how来提问。根据选择项的提示可知选D。
