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(xiàng)選擇題

If the compression ratio is increased on any diesel engine, ()

A.the expansion ratio will decrease
B.combustion will be slowed down
C.thermal efficiency will decrease
D.thermal efficiency will increase

微信掃碼免費(fèi)搜題