Question

—You can't imagine ________ fantastic fun online chatting is.
—Really？But it may cause a lot of trouble sometimes.

A．what

B．how

C．why

D．so

Answer 1

A

imagine后接了一個(gè)由what引導(dǎo)的賓語從句，該賓語從句是一個(gè)“what＋adj.＋不可數(shù)名詞＋主＋謂”結(jié)構(gòu)的感嘆句，故A正確。