问题：
[单选] Valve overlap is the period during which （）.
the inlet valve is open。the exhaust valve is open。both valves are closed。both valves are ope。
问题：
[单选] Vee-type engines have the connecting rods from two cylinders connected to each （） of the crankshaft.
throw。web。main bearing。deflectio。
问题：
[单选] Vents are led from the engine to head tank （） from the cooling water.
for the release of air。for the release of water。in order to the release of air。because the release of air。
问题：
[单选] Vents are led from the engine to the head tank for the release of （） from the cooling water.
air。heat。sludge。steam。
问题：
[单选] When a crankshaft （） outside the engine, it should be carefully supported in a manner which will avoid imposing high bending moments on it.
has to be handled。may be handled。has being handled。will be handling。
问题：
[单选] When a crankshaft has to be handled outside the engine, it should be carefully supported in a manner which will avoid （） high bending moments on it.
compressing。interposing。imposing。pounding。
问题：
[单选] When the follower is on the base circle of the cam, the pump plunger is at the （） of its stroke.
top。middle。bottom。any of the above。
问题：
[单选] When the order （） is received from the bridge, the main air stop valve in the starting air line should be shut.
stand-by engine。full ahead。finished with engine。full away。
问题：
[单选] When the starting air valve closes on one cylinder, another starting air valve has （） opened on another cylinder whose piston has just commenced its downward stroke.
just。nearly。merely。already。
问题：
[单选] When to remove scale from the cooling spaces, acid solution （） in the system can be tested from time to time by putting some on to a piece of lime.
strength。dense。percentage。velocity。
