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

<pre id="vzzrk"><strong id="vzzrk"></strong></pre>

<dd id="vzzrk"></dd>

<ruby id="vzzrk"><xmp id="vzzrk"></xmp></ruby>

<dl id="vzzrk"></dl>

單項選擇題

If a refrigeration compressor is running continuously without lowering temperature as normal in the refrigerator, the trouble may be （）.

A.excessive condenser cooling water
B.warm food in the refrigerator
C.a shortage of refrigerant
D.s shortage of compressor oil

你可能感興趣的試題

單項選擇題

Thermostatic expansion valve are （）.

A.either all the way open or all the way closed
B.normally open
C.throttled depending on load
D.controlled by suction pressure

單項選擇題

When a hydraulic vane pump is working, which of the following is in contact with the vanes?（）
(1) the rotor
(2) the internal surface of the housing
(3) the external surface of the housing

A.(1) only
B.(2) only
C.(1) and (2)
D.(1), (2) and (3)

<pre id="5rb3v"><acronym id="5rb3v"></acronym></pre>

<pre id="5rb3v"><acronym id="5rb3v"></acronym></pre>