单项选择题
A.being bolted B.bolted C.bolting D.to be bolted
The scavenging air ports are located at （） that they ar...
单项选择题The scavenging air ports are located at （） that they are just exposed by the upper edge of the piston when the piston is in the bottom dead center position.
A.so a height B.such a height C.so high D.such high
The rising of the exhaust temperature in manifold pipe ...
单项选择题The rising of the exhaust temperature in manifold pipe may NOT result from （）.
A.too great a loading B.fouled turbocharger C.bad combustion D.excessive air
The rim of the piston may contain cut-out portions to a...
单项选择题The rim of the piston may contain cut-out portions to accommodate （） when they open.
A.the gases B.the air C.the valves D.the injectors
