crack表示中文（）。

1、loop表示中文（）。

loop表示中文（）。A卷取机B张力C活套

2、Small crack in the crankshaft bearing

Small crack in the crankshaft bearing surface of a diesel engine are an indication of（）Acorrosion frettingBinsufficient lubricationCabnormal wearDfatigue failure

3、The lengthening of a crack formed in t

The lengthening of a crack formed in the shell plating of a ship may be prevented by （）.Awelding brackets across both ends of the crackBchi...

4、Cracks may be prevented from developin

Cracks may be prevented from developing at the corners of welded plating inserts by（）.Asquaring the cornersBrounding the cornersCplug welding the cornersDslot welding the corner

5、Cracking of a diesel piston crown can

Cracking of a diesel piston crown can result from（）AExcessive piston to liner clearanceBThe underside of the piston crown being excessively dirty lowering the rate of heat transferCFaulty nozzle sprayDAll of the above

6、裂缝（crack；fissure）

裂缝（crack；fissure）