新安装的变压器充电时，应将其差动保护（）。 ["投入","退出","投入，退出均可"]
Flashback Database is enabled in your Oracle 10g database. One of your database users erroneously purged an important table residing in his schema. The table was purged sometime between 10：00 P.M. and 10：30 P.M. The next day， you decide to flash back the database. Before you flash back the database， you want to ensure that you have all the necessary flashback data. Which dynamic performance view must you use to determine whether you have the required flashback data to recover the purged table？（） [" V$DATABASE"," V$UNDOSTAT"," V$FLASHBACK_DATABASE_LOG"," V$FLASHBACK_DATABASE_STAT"]
一台三相笼型异步电动机是否全压启动要看电动机容量与（）的关系。 ["供电变压器的容量","供电开关设备的容量","接触器的容量","熔断器的容量"]
The application workload on your database is same between 10 a.m. and 11 a.m. on weekdays. Suddenly you observe poor performance between 10 a.m. and 11 a.m. in the middle of the week. How would you identify the changes in configuration settings， workload profile， and statistics to diagnose the possible causes of the performance degradation？（） ["by using the SQL access advisor","by using the Automatic Workload Repository report","by running the Automatic Database Diagnostic Monitor （ADDM）","by using the Automatic Workload Repository Compare Period report","by analyzing the output of the V$ACTIVE_SESSION_HISTORY view"]
水电站大坝安全检查分为日常巡查、（）、定期检查和特种检查。 ["季度详查","年度详查","每月检查查","以上都不对"]
单吸离心泵轴向推力产生的主要原因是叶轮缺乏（）。
