问题补充：
---- What are you doing here now?
---- I’m thinking chatting with my good friends.
A. how fun to
B. how to fun with
C. what to have fun
D. how to have fun
答案：
A. how fun to
B. how to fun with
C. what to have fun
(答案→)D. how to have fun
解析：have fun为固定搭配，后面跟动名词，句意:—你在这儿干什么？—我正考虑如何与我的好朋友快乐地聊天。结合语境可知选D。
