单项选择题
A.gas oil B.diesel oil C.chemical compound D.Freon-12
The injector pump is operated by a cam which drives the...
单项选择题The injector pump is operated by a cam which drives the plunger （）.
A.top and bottom B.to and fro C.up and down D.back and forth
单项选择题The injector pump is operated by a cam which drives the （） up and down.
A.piston B.drum C.plunger D.barrel
The injector pump is operated by a cam which drives （） ...
单项选择题The injector pump is operated by a cam which drives （） up and down.
A.the needle valve B.the plunger C.the piston D.the cylinder
