下面关于楼梯构造要求的叙述中,( ) 正确。
A. 每个梯段的踏步数在3~18步
B. 允许坡度23-45度
C. 足够通行宽度即可
D. 平台宽度不小于1.5m
E. 踏步高和踏步面宽之和一般为450mm
But for your support then, I don’t think we ____the task.
A. can manage
B. could have managed
C. could manage
D. can have managed
His parents suggested that he ____ at home preparing the lessons, but he disagreed.
A. stay
B. staying
C. stays
D. stayed
You ____ all right now if you____ to the doctor then.
A. would be; had listened
B. would have been; had listened
C. would be; listened
D. would have been; listened
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