电泵井声测动液面时,对于油套环空间存在()或(),测试结果往往误差较大。
参考答案:大量泡沫段;死油段的井
I searched the Internet for a long time, but I couldn't find ______. [ ]
A. something useful
B. useful something
C. anything useful
D. useful anything
一般来说,气温直减率愈大,大气愈不稳定,反之气温直减率愈小,大气就愈稳定,若气温直减率为负值,即为()。