单项选择题
A.low compression
B.air-bound fuel system
C.improper spark
D.change in viscosity
单项选择题 If a diesel engine starts firing, but is unable to come up normal speed, either without load or even under a small load, the cause may be （）
单项选择题 Air in the fuel can cause（）
单项选择题 Which of the following operating procedures should be carried out immediately after any diesel engine is started?（）