99色精品-9色在线-99色在线-99色视频国产欧美日产一区二区三区_亚洲精品亚洲人成在线观看_四虎在线精品永久观看_免费一级a一片久久精

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>