问题：
[单选] Before replacing a piston you should check the rings to see that all clearances and gaps are within the permissible （）.
deflection。discrepancy。error。tolerance。
问题：
[单选] Before starting the engine the air bottle should be （）.
pumped up。loaded。discharged。opened。
问题：
[单选] Before starting the turning gear, （） should be worked by hand to minimize corrosive action on the liners.
the indicators。the starting valves。the cylinder lubricators。the turning gear。
问题：
[单选] Blow-off of the relief valves of the main cylinders during operation indicates （）.
the cylinder cover is cracked。the injector holes is clogged。the cams are not properly set。fuel pump is leaking。
问题：
[单选] Bridge gauge can be used to measure （） of a diesel engine.
diameters of journals。deflections of crankwebs。diameters of crankpins。none of the above。
问题：
[单选] Care and cleanliness are required when installing diesel fuel filters （）.
to prevent the fuel system from becoming air-hound。to prevent the fuel system becoming clogged with dirty particles。both of the above。to prevent the lubricating oil from leaking out of the filter element。
问题：
[单选] Cast iron carrier rings, （） machined grooves, are provided for all the pistons.
caulked into。caulking into。pressed into。screwed into。
问题：
[单选] Charging is the filling of the engine cylinder with a supply of （） for compression.
water。fresh air。fuel oil。ga。
问题：
[单选] Charging is the filling of the engine cylinder with a supply or charge of fresh air （） compression.
to need。ready for。want to。going to be。
问题：
[单选] Charging-air pressure increases if there is incorrect combustion and drop in the （） of the diesel engine.
machine efficiency。machinery efficiency。mechanical efficiency。mechanics efficiency。
