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

<thead id="9gpmi"><cite id="9gpmi"></cite></thead>

單項(xiàng)選擇題

If no gaskets are used in the piping joints of a Freon system, the joints must be（）

A.finished joints
B.welded joints
C.ground joints
D.soldered joints

你可能感興趣的試題

單項(xiàng)選擇題

If the temperature in the icebox is too high, the trouble could be（）

A.a clogged scale trap
B.air in the system
C.automatic controls not functioning properly
D.insufficient cooling water to the condenser

單項(xiàng)選擇題

Air or noncondensable gas is removed from a refrigeration system by a （）

A.separating chamber
B.system of baffles
C.purge valve
D.vacuum reducing valve

<ins id="jrvy7"></ins>