A. In good order. B. Often fails. C. Out of order.发生故障 D. Just so so.
At high temperature and low pressure. B. At low temperature and high pressure. C. At low temperature and low pressure. D. At high temperature and pressure.
A. Water-tube boiler. B. Fire-tube boiler. C. Exhaust boiler. D. Composite boiler.
A. Boilers. B. Water-tube boiler. C. Fire-tube boiler. D. Steam.
A. Fire-tube boiler. B. Water-tube boiler. C. Exhaust boiler. D. Scotch boiler
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