When a crankshaft has to be handled outside the engine, it should be carefully supported in a manner which will avoid （） high bending moments on it.

A.has to be handled
B.may be handled
C.has being handled
D.will be handling

A.air
B.heat
C.sludge
D.steam

A.for the release of air
B.for the release of water
C.in order to the release of air
D.because the release of air