消防应急照明回路沿电缆管井垂直敷设时，公共建筑应急照明配电箱供电范围不宜超过（）层，住宅建筑不宜超过16层。
A.4
B.5
C.6
D.8
参考答案：D
Don't sigh over the small achievement. _____ , and I'm sure if you keep at it, you'll see the light at the end of the tunnel!
A．Lookers-on see most of the game
B．Constant dropping wears away the stone
C．The world is your oyster
D．Lost time is never found again
下钻应采用限速措施。下钻大钩载荷超过（）kN应使用辅助刹车。
A.100；
B.200；
C.300；
D.500。
