问题
选择题
The students are too _____ to keep their eyes open in class because of staying up late.
A．sleeping
B．asleep
C．sleep
D．sleepy
答案
答案：D
题目分析: 句意因为熬夜，学生们在课堂上困得睁不开眼了。Sleep睡觉，asleep醒着的，sleepy困的。Too.+adj+to...太......而不能......,固定句型，故选D。