When an engine is starting and has got a s
题型：单项选择题
问题：
When an engine is starting and has got a sufficiently high speed, say about 20 rpm,（）
A.the starting air supply is cut off and fuel is injected into the cylinders
B.the fuel feeding is cut off and the turning gear is put in
C.the starting air supply is cut off and turning gear is taken out
D.the electric blower is shut down and fuel is injected into the cylinders