Why would you use the following FLASHBACK TABLE command？（） FLASHBACK TABLE emp TO TIMESTAMP （’11：45’，’hh12：mi’）； ["to undo the changes made to the EMP table since the specified time","to restore the EMP table that was wrongly dropped from the database","to view the transactions that have modified the EMP table since the specified time","to view the changes made to the EMP table for one or more rows since the specified time","to recover the EMP table to a point in time in the past by restoring the most recent backu"]
在动火作业前，必须使用可燃气体检测仪监测可燃气体，浓度必须小于（）%。 ["0.2","0.4","0.5","0.8"]
一般情况下，输电距离越大，所用的电压等级越高，其原因是（）。
What types of host connectivity are available on the Storwize V7000?（） ["Fibre Channel and SAS ","Fibre Channel and iSCSI ","Fibre Channel, iSCSI and SAS ","Fibre Channel, iSCSI and InfiniBand&e"]
滑模施工，对于乘人电梯及罐笼等设施，必须设安全保险机构，并经（）检查合格后，方可启用，运行期间尚应定期检查。 ["质监机构","监理单位","安全部门","项目法人"]
杜朗口三三六模式主要含义是什么？
