单项选择题
A.the inlet valve is open B.the exhaust valve is open C.both valves are close D.both valves are open
The outside diameter of the pipe is （） the diameter of ...
单项选择题The outside diameter of the pipe is （） the diameter of the bore of the piston rod, the result being that an annular space formed between the piston rod and the pipe.
A.less than B.greater than C.equal to D.twice larger than
The operation between two fuel injections is called a w...
单项选择题The operation between two fuel injections is called a working cycle, which consists of a fixed sequence of eventsWhat does "which" mean in this sentence?（）
A.a working cycle B.the operation C.two fuel injections D.events
