轿厢安全钳应装一个电气装置，其作用是（）。
A、操纵安全钳
B、与限速器相通
C、在安全钳动作之前或同时切断电源
D、测量动作速度
参考答案：C
The meat is dear and eating meat is bad for your health. [ ]
A. too much; much too
B. too much; too much
C. much too; too much
D. much too; much too
设备上接管的外伸长度应考虑（）
A.所设置的保温层厚度
B.便于安装螺栓
C.便于安装加固结构
D.A和B
