密封油泵开车正常后,由润滑油过滤器后抽出一股润滑油作为密封油泵的吸入。
参考答案:对
I am sorry that I have kept you ______ me so long. [ ]
A. waiting
B. waiting for
C. to wait
D. to wait for
安培是()的单位。
A.电流
B.电压
C.电功率
D.电能