问题
选择题
—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
答案
答案：A
imagine后接了一个由what引导的宾语从句，该宾语从句是一个“what＋adj.＋不可数名词＋主＋谓”结构的感叹句，故A正确。