题目内容：

John was so sleepy that he could hardly keep his eyes _______.
A.open
B.to be opened
C.to open
D.opening
选择原因?

优质解答

A,
keep +形容词 (保持..状态,open在这里是形容词,打开的）
John was so sleepy that he could hardly keep his eyes open
约翰如此困倦以至于眼睛都快睁不开了