— You can’t imagine great fun chatting online is.— Really? But it may cause you a lot of t

问题补充：

— You can’t imagine great fun chatting online is.

— Really? But it may cause you a lot of trouble.

A. what

B. how

C. why

D. whether

答案：

(答案→)A. what

B. how

C. why

D. whether

解析：本题就是考察great fun chatting online is.这一句感叹句，应该选择用what，故选答案为A