97免费在线观看视频,亚洲综合自拍网,黄色毛片免费观看,热久久综合网,免费看日产一区二区三区 狠狠操av,久久久涩涩涩,在线精品免费视频,人人插天天干,久久91精品国产91久久

單項(xiàng)選擇題

Crankcase sweating in a refrigeration system is caused by ().

A.a stuck solenoid valve
B.a shortage of refrigerant
C.too much oil in circulation
D.too much superheat

微信掃碼免費(fèi)搜題