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

The () engine is used for alternators and sometimes for main propulsion with a gearbox to provide a propeller of between 90 to 120 rpm.

A.four-stroke
B.two-stroke
C.slow speed
D.reversible

微信掃碼免費搜題