绞车的闸把及杠杆等应动作灵活可靠。
参考答案：对
Mozart’s birthplace and the house ______ he composed“The Magic Flute”are both museums now.
A．where
B．when
C．There
D．that
发生突发性质量事故，事故单位要在( )小时内电话向有关单位报告。
A．2 B．8C．6 D．4
