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（）。
You are installing Oracle Database 11g on a machine. When you run the installer， the Oracle Universal Installer（OUI） shows the message that says one of the product-specific prerequisite checks has failed：Checking available swap space requirements ...Expected result： 1512MBActual Result： 1018MB Check complete. The overall result of this check is： Failed <<<< Problem： The system does not have therequired swap space. What happens to the installation in this situation（） It can be continued.。 It resizes the swap space automatically when you proceed further.。 It can be continued， but the instance cannot be started without increasing the swap space.。 It shows a message saying one or more prerequisite checks have failed and the installation cannot proceed。
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。
What is the output of this command?（） A list of files that require a backup within 3 days。 A list of files requiring more than 3 days of archivelogs to apply。 A list of files that RMAN recommends be backed up only once in every three days, based on low volatility。 A list of files for which a backup as already been performed in the last three days and which is required to be backed up again based on the high number of transactions performed on them。
A subquery can be used to （）.
