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

The working cycle of a four-stroke diesel engine consists of four events:（）
(1) compression
(2) expansion
(3) exhaust
(4) suctionThe correct sequence is

A.(4)-(2)-(3)-(1)
B.(4)-(3)-(1)-(2)
C.(4)-(3)-(2)-(1)
D.(4)-(1)-(2)-(3)

微信掃碼免費(fèi)搜題