危险度由( )决定。
A.事故发生的可能性或严重性 B.事故发生的广度和深度C.发生事故的可能性和严重性 D.发生事故的广度和深度
参考答案:C
You'd better wake him up at once. He _____ for eleven hours already. [ ]
A. has been asleep
B. has fallen asleep
C. has gone to bed
D. has gone to sleep
关于儿童在游戏时的表情,正确的说法是()
A.茫然发呆
B.总是专注认真的
C.总是在笑
D.有多种表情