英语26.I ------ while reading the English textbook.Luckily,my

英语26.I ______ while reading the English textbook.Luckily,my roommate woke me up in time!26.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为什么