问题补充：
---I often chat with my friends on the Internet.
---You are so smart! Will you please tell me ?
A. how to do
B. how to do it
C. how to use
D. when can I use it
答案：
A. how to do
(答案→)B. how to do it
C. how to use
D. when can I use it
解析：句意：我经常和我的朋友在网上聊天。——你太聪明了！你能告诉我如何做吗？how是疑问副词，不能用作宾语，故选项AC结构错误，宾语从句一般用陈述语序，故选项D语序错误，选B。
