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="j97dd"><legend id="j97dd"></legend></pre><dl id="j97dd"><strong id="j97dd"></strong></dl>

單項(xiàng)選擇題

Which of the following statements concerning fire-tube boilers is correct?（）

A.Combustion gases flow through the tubes
B.Flames impinge on the tubes
C.Combustion occurs in the tubes
D.Water flows through the tubes

你可能感興趣的試題

單項(xiàng)選擇題

A diesel engine cooling water system with a pH factor of 30 indicates a condition of （）.

A.slight acidity
B.slight alkalinity
C.excessive alkalinity
D.excessive acidity

單項(xiàng)選擇題

Fuel injectors used in heavy fuel oil systems are usually provided with cooling to reduce（）.

A.cold corrosion of the nozzles
B.fuel viscosity for better atomization
C.carbon accumulation on the nozzles
D.fuel detonation in the cylinders

<ins id="wjlqv"><output id="wjlqv"></output></ins>

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

<menu id="wjlqv"><strong id="wjlqv"></strong></menu>

<pre id="wjlqv"><strong id="wjlqv"></strong></pre><ruby id="wjlqv"></ruby>