99色精品-9色在线-99色在线-99色视频 国产欧美日产一区二区三区_亚洲精品亚洲人成在线观看_四虎在线精品永久观看_免费一级a一片久久精

單項(xiàng)選擇題

If the head pressure is too high,()

A.the relief valve should open before the high-pressure cutout
B.the relief valve should open and let excess refrigerant go to receiver
C.the high-pressure cutout switch should operate before the relief valve opens
D.close in on the suction valve

微信掃碼免費(fèi)搜題