各缸进气门的微开量比排气门都小,表明进、排气门的配气相位均()。
A.延迟
B.提前
C.正常
参考答案:A
As he didn’t have much money, he had to ____ a second- hand computer for his work.
A.pick up
B.give up
C.look up
D.take up
发电机在热状态下,全部励磁回路的绝缘电阻不小于()。
A、0.1兆欧
B、0.5兆欧
C、1兆欧
D、1.5兆欧