单项选择题
A.to interfere with
B.interfering with
C.to help scavenging
D.helping scavenging
单项选择题 The diffuser prevents pressure pulses from one cylinder （） another during operation.
单项选择题 The diesel engine must be started before it can run by it self For this purpose （） has to be used.
单项选择题 The diesel engine is a type of internal combustion engine which ignites the fuel by injecting it into hot, high pressure air in a （）.