问题补充:
I while reading the English textbook. Luckily, my roommate woke me up in time !
A. had fallen asleep
B. have fallen asleep
C. fell asleep
D. fall asleep
答案:
A. had fallen asleep
B. have fallen asleep
(答案→)C. fell asleep
D. fall asleep
解析:根据woke(wake 的过去式)可以判断,这里谈论的与“现在”无关,因此可以排除B和D两项。I是在读书期间睡着的(while reading),而不是在之前睡着的,所以A项也是不恰当的。