单项选择题 One advantage of a flash distilling plant when compared to a submerged tube distiller is（）

单项选择题 Sludge may be formed in the oil in the crankcase of a reciprocating air conditioning compressor as a result of （）

单项选择题 Which of the processes listed would be the most satisfactory method to use to lower the humidity of the air being circulated by an air conditioning system?（）