I__asleep because it took me a long time to relaize that the telephone was ring
问题描述：
I__asleep because it took me a long time to relaize that the telephone was ring
a could have fallen b should have fallen c must have fallen d must not have fallen
答
选C,must have done表示对过去肯定的推测.此句话的意思是：我刚刚肯定是睡着了,因为过了很久我才意识到电话响了.