单项选择题
The viscosity regulator controls the fuel oil temperature （）provide oil at the correct viscosity for combustion.
A.in order that B.because of C.in order to D.owing to
单项选择题 To avoid scavenge fires occurring the engine timing and equipment maintenance （）.
单项选择题 Combustion knock can occur in the cylinders of a diesel engine under any condition permitting （）.
单项选择题 Which of the following may cause that an engine doesnt turn on starting air?（）
