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

With ducted air conditioning systems, the modern tendency is to use（）

A.central air conditioning system
B.high velocity system
C.low velocity system
D.single duct system

你可能感興趣的試題

單項選擇題

The（） only allows for adjustment of temperature in each room by the occupant manually controlling the air volume admitted.

A.central air condition system
B.high velocity system
C.low velocity system
D.single duct system

單項選擇題

The volute of centrifugal pump also acts as a diffuser converting （）into pressure head.

A.mechanical energy
B.heat energy
C.potential energy
D.kinetic head

<em id="fygiw"></em>

<pre id="fygiw"><legend id="fygiw"></legend></pre>

<blockquote id="fygiw"></blockquote><ins id="fygiw"></ins>