单项选择题
A.loss of flow in the fuel system
B.loss of pressure in the air system
C.loss of flow in the lubricating system
D.loss of pressure in the lubricating system
单项选择题 Engine fuel pump index is （）.
单项选择题 Engine （） refers to the relative time of position of crank, at which each operation during the cycle is commenced and is completed.
单项选择题 Engine （） refers to the relative time of position of crank, at which each operation during the cycle is commenced and is completed.