单项选择题
A.if B.as C.unless D.when
The crank throws are displaced from （） to obtained the ...
单项选择题The crank throws are displaced from （） to obtained the same number of degrees between the different crank throws.
A.one another B.the other C.each other D.each others
The crank pin journal is provided with large bores for ...
单项选择题The crank pin journal is provided with large bores for （）.
A.lubrication B.cooling C.balancing purpose D.ventilation
The crank chamber oil （）.A.can be recoveredB.is only su...
单项选择题The crank chamber oil （）.
A.can be recovered B.is only supplied to cylinders C.only feeds the main bearing D.is a kind of detergent
