问题：
[单选] The cap and new shell are tightened up and then removed and the thickness of the wire measured by （）.
a bridge gauge。a micrometer。a thermometer。a indicator。
问题：
[单选] The carbon deposits on the piston crown and in the ring grooves （）.
should be scraped。should be derusted。should be drilled out。to be brushed off。
问题：
[单选] The cast iron（）for the cross-head are attached to the top section and seal off the crankcase.
cylinder cover。cross-head shoes。guide-ways。scavenging boxe。
问题：
[单选] The cast iron guide-ways for （） are attached to the top section and seal off the crankcase.
the connecting rod。the cross-head。the piston rod。the air box。
问题：
[单选] The cleaned heated oil, after passing through the centrifuges, is to be pumped to a （）.
settling tank。service tank。ballast tank。drain tank。
问题：
[单选] The common method of applying oil to the cylinder walls is by means of small pump assembled in units, known as （）.
mechanical lubricator。lubrication function。forced feed system。bearing lubricatio。
问题：
[单选] The complete assembly of bedplate, A-frames and cylinder block is held together by （） to form a rigid structure.
tap-bolts。jack-bolts。tie rods。fitted rod。
问题：
[单选] The compressed air is admitted to each cylinder through a cam operated by starting air valve when the piston has just passed its （）.
BDC。TDC。BBDC。ATDC。
问题：
[单选] The compressed air is supplied by （） to the air reservoirs.
compressors。forced fans。ventilators。generator。
问题：
[单选] The conclusion that mechanical efficiency is always （） 100 percent is correct.
small than。more than。little than。less tha。
