下列密封中，属于接触式密封的是（）。 ["机械密封","填料密封","迷宫密封","波纹管密封"]
You are performing flashback of the ORDERS table in the Scott’s schema because some important data is deleted in the table by mistake. The SCN number was 771513 at the time of deletion. You issued the following statement to perform Flashback Table： SQL> FLASHBACK TABLE ORDERS TO SCN 771513； What is the prerequisite to perform Flashback Table？（） [" You must configure OMF in your database."," You must enable block change tracking feature in your database."," You must enable ROW MOVEMENT feature on the ORDERS table."," You must use the Flashback Version Query before using the Flashback Table feature."]
A customer has an LPAR with 4 dedicated cores on a POWER7 server with SMT4 enabled. How many logical processors are presented to an application running on this LPAR?（） ["4","8","16","32"]
以下哪种行为属于投标人串通投标行为（）。 ["招标人预先内定中标人","招标人向投标人泄露标底","投标人之间互相约定抬高报价","投标人向评标专家行贿"]
在事件处理程序中定义的变量，其生命周期仅限于该过程。
完整测定大肠菌群时间是（）小时。
