目前,国家规定的职业病有()种。
A. 99
B. 101
C. 103
D. 108
What provides little or no indication that a vessel is dragging anchor? ()
A. Increasing radar range to a fixed object ahead
B. Drift lead with the line leading perpendicular to the centerline
C. Vibrations felt by placing a hand on the cable
D. Changing bearings to distant fixed objects abeam
水库蓄水、深井注水、矿山开采及核试验,在特定的工程地质环境均可诱发()
A. 泥石流
B. 地面变形灾害
C. 地下水增加
D. 破坏性地震
每个分、集水器分支环路不宜多于几路?分支环路供回水管上阀门设置有何要求?