问题：
[单选] The （） or balance tank collects the re-circulated fuel oil.
overflowing。sump。bilge。buffer。
问题：
[单选] The （） in the injector will lift at a pre-set pressure which ensures that the fuel will atomize once it enters the cylinder.
needle valve。nozzles。piston。spring。
问题：
[单选] The abbreviation BDC means （）.
Boston Diesel Company。base circle diameter。switch board case。bottom dead center。
问题：
[单选] The abbreviation TDC means （）.
top dead center。temperature difference center。time delay dock。top diesel company。
问题：
[单选] The amount of lubricating oil in the drain tank should be checked by （）.
measuring。sounding rod。metering。weighting。
问题：
[单选] The auxiliary engine and a cgenerator can be connected with （）.
cam。crosshead。bulge。coupling。
问题：
[单选] The bearing shells depend on the accuracy of （） to held them in a truly circular shape.
the gap。the clearance。the bore。the housing。
问题：
[单选] The bed-plate is secured in the longitudinal direction by means of bolts known as （）.
end-chock bolts。side-chock bolts。through bolts。tie rod。
问题：
[单选] The bore of each cylinder is formed in a liner which can be （） when worn out.
welded。replaced。drilled again。bored。
问题：
[单选] The burning of the fuel adds more heat to the air charge, causing it to expand and force the engine piston to do work on the crankshaftWhat does “it” mean in this sentence?（）
the burning。the fuel。the air charge。the engine pisto。
