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

<em id="4q2rc"></em>

單項選擇題

What will NOT increase friction of a liquid flowing in a pipe and cause a loss of suction head?（）.

A.Bends in the piping
B.Slowing the pumping rate
C.Pipeline valves
D.Backing rings for pipe welds

你可能感興趣的試題

單項選擇題

What normally helps in detecting escaping gas? （）

A.Running hand along pipe
B.Red flame
C.Odor
D.Increase the line pressure

單項選擇題

What is used to test a tank for oxygen content?（）

A.Combustible gas indicator
B.Vapor indicator
C.Atmosphere analyzer kit
D.None of the above

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

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