问题
选择题
Nick stayed up really late last night. So this morning he by the time the class began.
A. had fallen asleep B. had showm up C. had realized
答案
答案：A
题目分析： stay up熬夜，by the time直到，句意：Nick昨晚熬夜到很晚，因此今天上午直到上课他也没有起来。fall asleep入睡，睡觉。began是过去时，过去的过去用过去完成时，故选A。