单项选择题 The presence of air in the condenser of a refrigeration system will （） the condensing pressure.

单项选择题 Which of the following may cause that excessively warm water leaves the condenser in a refrigeration plant? （） (1) too little cooling water (2) too much cooling water (3) too warm cooler water

单项选择题 Which of the following may cause that the compressor cuts off on high pressure cutout in a refrigeration plant? （） (1) faulty condensing (2) too few refrigerant (3) high discharge pressure