单项选择题
Which of the following descriptions best identifies the operating principal of a flash-type evaporator?（）
A.Sea water is heated to boiling temperature while under a vacuum B.Sea water is passed over heated plates in a thin film C.Heated sea water is injected into a vacuum chamber D.Sea water is forced through a heated eductor
单项选择题 Which of the listed conditions can lead to cavitation气穴in a centrifugal pump?（）
单项选择题 A centrifugal bilge pump requires priming （）.
单项选择题 The process of removing moisture from air is known as（）.
