单项选择题 There is an injection pump for each cylinder, which is usually operated once every cycle by （） on the camshaft.

单项选择题 There is a （） system lubricating the running gear and cooling the piston and sometimes lubricating the cylinders.

单项选择题 There is （） in any water cooling system for a diesel engine allowing for expansion and water make-up in the system as well as air vent and chemicals addition.