Awasteheatboilerisinstalledonsomedieselpropelledvesselsto（）.
A. providesteamforemergencypropulsion
B. providesteamfortheturbo-generator
C. heatthewastewatertanks
D. steamforwarmingengines
不属于商业信用筹资的优点的是（）
A. 筹资风险小
B. 筹资成本低
C. 限制条件少
D. 筹资方便
Camshaftsareusuallydrivenbytiminggearsor（）.
A. pushrods
B. chaindrives
C. rockerarms
D. flywheels
Watersidescaleinafire-tubeboilermaycause（）.
A. increasedheattransfer
B. firesideerosion
C. highsteamdemand
D. overheatedtubes
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