LV型高度调整阀的动作延迟时间试验标准为()。
A.(2±1)S
B.(3±1)S
C.(4±1)S
D.(5±1)s
参考答案:B
—What would you like ______ supper?
—Noodles. [ ]
A. in
B. after
C. from
D. for
设备检修时切断电源处采取的措施是()。
A.加锁或专人监护并悬挂“有人作业不准送电”警示牌
B.专人监护
C.加锁