附着式升降脚手架升降时不用划定安全警戒范围。（）
参考答案：错
–- -What does your grandmother do? ---_____________________.
A．She likes her work
B．She is a clerk.
C．She is busy
D．She is working
自停报警结束方式不包括（）.
A.机车信号变为允许信号
B.低速接点或压力接点切除
C.非定时切除
