在用电梯配备司机是()的需要。
A.领导
B.乘客方便
C.安全运行管理
D.电梯设计原理
参考答案：C
the students in this primary school is about four thousand, and of them are boys.[ ]
A. A number of; three fifth
B. A number of; three fifths
C. The number of; three fifth
D. The number of; three fifths
乳化液泵站泵和液箱紧固件滑动轴承温度不超过（）℃
A.55
B.65
C.75
D.85
