建筑高度大于()m且设置电梯的高层仓库，每个防火分区内宜设置一台消防电梯。
A.32
B.24
C.16
D.20
参考答案：A
We tried _____ to persuade him to stay home, but at last, he went to the construct site in spite of his illness.[ ]
A. in vain
B. in return.
C. in fact
D. in time
不需要事先建立就可以使用的变量是（ ）。
A． Current Y
B． Picture
C． Current x
D． Stretch
