The majority of medium speed and high speed marine diesel engines for main or auxiliary drive operate on the （） cycle.

[单选题]Crankshafts of medium speed engines are （） from a single piece of steel.A . unusually solid weldedB . never be solid forgedC . almost invariably solid forgedD . almost invariably be welded

[单选题]On a medium-speed main propulsion diesel engine, the crank-pin or crank journalbearings receive lubricating oil from( ).A．a spindle lubricatorB．an oil jetC．internal splashingD．drilled passages in the crankshaft

[单选题]The high-speed data services for the interconnection of computer networks are usually referred to as ______ connections．A．LANsB．MANsC．WANsD．ATM

[单选题]Most medium and slow speed diesels are started by what medium?（）A . Electric starting motorsB . HydraulicsC . Compressed airD . Ether

[单选题]On a medium-speed main propulsion diesel engine, the crank-pin or crank journal bearings receive lubricating oil from （）.A . a spindle lubricatorB . an oil jetC . internal splashingD . drilled passages in the crankshaft

[单选题]Pistons of marine medium speed diesel engines may be made of （） in order to keep the weight down for balancing purpose at high speed.A . leadB . forged steelC . alloy steelD . aluminum alloy

[单选题]On a turbo-charged, medium-speed diesel engine, which of the following problems is an indication of a restricted air intake passage?（）A . Engine is hard to startB . Engine missesC . Surges at governed RPMD . Coolant temperature is too low

[单选题]High-speed rotating in a centrifugal purifier can produce a force （） larger than the force of gravity.A . many thousand timesB . between timesC . one timeD . at time

[单选题]You are really( )a risk to drive at such a high speed！A.followingB.passingC

[名词解释] 中/高费清洁生产方案（Medium/high Cost Cleaner Production Option）