单项选择题
A.height B.breadth C.depth D.length
Our jumbo boom can（）20 tons.A.liftB.riseC.elevateD.hois...
单项选择题Our jumbo boom can（）20 tons.
A.lift B.rise C.elevate D.hoist
On which type davit does the davit head stay at the sam...
单项选择题On which type davit does the davit head stay at the same height?（）
A.Radial B.Sheath-screw C.Quadrantal D.Gravity
On what type of pump would you find an impeller?（）A.Cen...
单项选择题On what type of pump would you find an impeller?（）
A.Centrifugal B.Gear C.Piston D.Vane
