You need to perform a block media recovery on the tools01.dbf data file in the SALES database by using Recovery Manager (RMAN).Which two are the prerequisites to perform this operation？（） You must configure block change tracking file。 You must have first level 1 backups for RMAN to restore blocks。 You must ensure that the SALES database is mounted or open。 You must have full or level 0 backups for RMAN to restore blocks。 You must take the tools01.dbf data file offline before you start a block media recovery。
A healthcare customer has an IBM System i server and an HP-UX server. They have high performance I/O， image-based， and archival applications. The customer has asked the IBM team for guidance on IBM DS8000 disk technologies. Which DS8000 disk technology would provide the best performance without regard to cost to meet the customer requirement（） 73 GB 15k and 300 GB 15k drives。 73 GB SSD and 2TB 7.2k drives。 146 GB 15k and 300 GB 15k drives。 146 GB 15k and 2TB 7.2k drive。
120型控制阀加速缓解阀由（）、加速缓解膜板、活塞杆、橡胶密封圈、夹心阀、加速缓解阀弹簧、止回阀、止回阀簧、顶杆、加速缓解阀套等组成。 主活塞。 加速缓解阀活塞。 递动杆。 稳定杆。
餐饮成本从不同角度有哪些分类？
健康成年人男性肺活量值大约为（），而女性则为2500～3500ml。 2000～3000ml。 2500～3500ml。 3000～3500ml。 3500～4000ml。
测绘单位可以从事测绘活动必要条件。（）
