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

The flash point of a residual fuel oil should be used to determine the highest temperature to which oil may be heated ()

A.for atomizing
B.for centrifuging
C.in a storage tank
D.in the re-circulating line

微信掃碼免費搜題