If a receptionist or anyone who welcomes visitors can successfully break the ice, it will of course help a lot. 
A、正确
B、错误

A.调节的油压较低，进气岐管真空度小；
B.调节的油压较高，进气岐管真空度小；
C.调节的油压较低，进气岐管真空度大；
D.调节的油压较高，进气岐管真空度大；