当阀监控系统检测到用阀存在短暂接地故障时往往投入旁通对。
参考答案：错
The TV play _____ for ten minutes when I turned on the TV. [ ]
A. had been on
B. had started
C. had begun
D. has been on
下列各项中，( )不属于工程项目建设招标应具备的前提条件。
A．建设用地征用完毕 B．建设项目已正式批准立项C．招标文件已经编制好 D．建设资金来源已经落实
