无码高清视频|成人自拍视频|欧美成人午夜无码A片秀色直播|草美女视频网站|美女被操网站在线观看

<dl id="1xcvr"></dl>

<ins id="1xcvr"><xmp id="1xcvr"></xmp></ins>

<dl id="1xcvr"></dl>

<ruby id="1xcvr"><xmp id="1xcvr"></xmp></ruby>

單項(xiàng)選擇題

If the flame from combustion in the cylinder of a four-stroke engine past the piston into the space below, the accumulation of flammable mixture would be ignited, thus resulting in （）.

A.the crankcase explosion
B.lifting of the cylinder safety valve
C.a scavenge fire
D.opening of the manhole

你可能感興趣的試題

單項(xiàng)選擇題

If the engine does start on air, but combustion does not immediately begin, the cause may not be （）.

A.low compression
B.failure of the fuel pump to discharge fuel
C.incorrect timing of fuel pump
D.turning gear being still on

單項(xiàng)選擇題

If the engine does start on air, but combustion does not immediately begin, the cause may be （）.

A.failure of the fuel pumps
B.starting air pressure too low
C.stop valve in air line closed
D.the turning gear still engaged