单项选择题
A.that the fuel valve is open B.if the air supply system is open C.if the water sprinkler system is open D.if the limit switch is on
If a gasoline engine turns over freely but will not sta...
单项选择题If a gasoline engine turns over freely but will not start，the cause is generally（）.
A.a defective ignition system B.low lube oil level C.weak valve springs D.too heavy a load
Each cylinder in a two stroke cycle engine experiences ...
单项选择题Each cylinder in a two stroke cycle engine experiences combustion（）.
A.once each crankshaft revolution B.twice each crankshaft revolution C.every other crankshaft revolution D.every fourth stroke
Centrifugal pumps have what advantage(s) over reciproca...
单项选择题Centrifugal pumps have what advantage(s) over reciprocating pumps?（）.
A.They are less expensive B.They are smaller for equivalent pumping ability C.They pump more cargo in less time D.All of the above
