单项选择题
A.renewed B.welded C.machined D.chromium-plated
There should be a lubricating oil （） between the main b...
单项选择题There should be a lubricating oil （） between the main beatings and the crankshaft.
A.film B.cap C.lacquer D.shell
There is an injection pump for each cylinder, which is ...
单项选择题There is an injection pump for each cylinder, which is usually operated once every cycle by （） on the camshaft.
A.a gear B.a cam C.a rod D.a miler
There is a （） system lubricating the running gear and c...
单项选择题There is a （） system lubricating the running gear and cooling the piston and sometimes lubricating the cylinders.
A.recirculating B.total loss C.cooling D.refrigeration
