牺牲阳极投入运行的测量项目不包含()。
A、电位
B、电流
C、电阻
D、电容
参考答案:D
I ______ for Beijing in a few days. Do you know when the earliest plane ______?
A.leaves, takes off
B.is leaving, is taking off
C.am leaving, takes off
D.leave, is taking off
取心钻进中钻井液短路,钻井泵上水不好,引起干钻,易造成“堵心”。