When a vacuum boiling evaporator works, the hot jacket water will pass over the tube stack and （） the sea water passing through the tubes.

（） is the production of pure water from sea water by ev...

单项选择题（） is the production of pure water from sea water by evaporation and re-condensing.

Which of the following can be used in hydraulic transmi...

单项选择题Which of the following can be used in hydraulic transmission system?（）

（） play a very important part in hydraulic systems by p...

单项选择题（） play a very important part in hydraulic systems by preventing interaction between different parts of the hydraulic circuit.