单项选择题
Static electricity may be built up by the（）.
A.flow of petroleum through pipes
B.spraying or splashing of petroleum
C.settling of solids or water in petroleum
D.All of the above
点击查看答案&解析
相关考题
-
单项选择题
Permission is kindly requested（）the ballast water.
A.pump out
B.to pump out
C.pumping out
D.be pumped out -
单项选择题
On a ship，a door that is required to be marked KEEP CLOSED is designed to（）.
A.prevent the passage of flammable gases
B.prevent the passage of poisonous vapors
C.delay the spread of heat and flames
D.maintain watertight integrity -
单项选择题
Limit switches are used on which davits?（）
A.Sheath-screw davits
B.Gravity davits
C.Radial davits
D.Quadrantal davits
