單項選擇題

Which of the following statements concerning energy is correct?（）

A.Energy can be created or destroyed
B.Energy may not be transformed
C.The total quantity of energy in the universe is always the same
D.None of the above

你可能感興趣的試題

單項選擇題

In a compression refrigeration cycle, the temperature of the liquid refrigerant experiences its greatest decrease in the（）.

A.evaporator
B.compressor
C.expansion valve
D.condenser

單項選擇題

Excessive oil foaming in the crankcase of a refrigeration compressor is most likely to occur（） when the compressor.

A.has continuously for a long period
B.suction pressure is below normal
C.oil level is below normal
D.starts after a long idle period

无码高清视频|成人自拍视频|欧美成人午夜无码A片秀色直播|草美女视频网站|美女被操网站在线观看

Which of the following statements concerning energy is correct?（）

你可能感興趣的試題

In a compression refrigeration cycle, the temperature of the liquid refrigerant experiences its greatest decrease in the（）.

Excessive oil foaming in the crankcase of a refrigeration compressor is most likely to occur（） when the compressor.