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

單項選擇題

Moisture should be kept out of an R-12 system because it tends to cause （）.

A.icing of the automatic controls
B.embrittlement of some parts of the automatic controls
C.sludge in the lubricating oil
D.all of the above

你可能感興趣的試題

單項選擇題

Black smoke coming from a boiler can be caused by （）.

A.low water level
B.high water level
C.excessively high fuel pressure
D.low oil temperature

單項選擇題

If a bilge pump failed to build up discharge pressure, you should check for （）.

A.excessive water in the bilges
B.a clogged suction strainer
C.oil in the bilges
D.All of the above

<dd id="hitxl"></dd>

<sup id="hitxl"><legend id="hitxl"><div id="hitxl"></div></legend></sup>

<pre id="hitxl"><legend id="hitxl"><s id="hitxl"></s></legend></pre>

<ruby id="hitxl"><small id="hitxl"></small></ruby>