体积量用符号“V”表示，在法定计算单位中，体积是用“立方米”或（）。 “公升”；。 “立升”；。 “升”；。
在需要保护的网络与可能带来安全威胁的互联网或其它网络之间建立的保护层，称为（） 屏蔽层。 应用层。 防火墙。 物理层。
The size of the largest datafile， data1.dbf， in your database is 30MB. You issued the following command： RMAN>CONFIGURE MAXSETSIZE 10MB； What will be the impact of the above setting？（） While performing the backup of the datafile，data1.dbf，one backup set is created.。 While performing the backup of the datafile，data1.dbf，two backup sets are created.。 While performing the backup of the datafile，data1.dbf，three backup sets are created.。 While performing the backup of the datafile，data1.dbf，the command for performing a backup of the datafile，data1.dbf，will fail.。
Examine the data in the EMPLOYEES and EMP_HIST tables: The EMP_HIST table is updated at the end of every year. The employee ID, name, job ID, and salary of each existing employee are modified with the latest data. New employee details are added to the table. Which statement accomplishes this task?（）
。
。
。
。
只作支承转动的零件的轴，叫（）；既支承转动零件，又传递动力，本身也转动的轴，叫（）；只传递动力的轴，叫（）。
In a design situation, there are multiple character sets that can properly encode your data. Which three should influence your choice of character set?（）
