Scarcely ______ asleep when a knock at the door awakened herA. she had fallen B. she had fallen into C. had she fallen D. fell she 为什么选C

scarely绝不，否定词前置要使用部分倒装

scarely是否定词，当用在句首时，句子要倒装，并且用过去完成时。表示刚要。。。就。。。
同样的还有hardly。。when

scarcely几乎不,简直不,否定意义的词在句首,句子部分倒装,所以选C.类似的还有：hardly,no sooner,等.如：
Hardly had we got there when it began to rain.
No sooner had they arrived than the meeting started.

Scarcely提前了，句子要倒装。正常语序是she had fallen xxx scarecely xxx。
但是这里Scarcely提前了，主谓要倒装。
读的多了，自然就有语感了。