题目内容：

1.You can't imagine _______ when they received these nice Christmas presents.
A.how they were excited B.how excited they were
C.what excitement they were D.what were they excited
为什么不能选C

优质解答

what和how都可用在祈使句的开头,但how加上形容词,而what要加上数词和形容词,再加上名词,因此这里只能选B,而且B是陈述句语序.