Your database operates in ARCHIVELOG mode. User/x7fmanaged consistent backups are performed every Sunday night. On Tuesday， client A drops a table at 8：00 a.m. as follows： SQL> DROP TABLE cust_ord PURGE; Table dropped. Client B executes a query at 9：00 a.m. on the same table as follows： SQL> SELECT * FROM cust_ord; SELECT * FROM cust_ord * ERROR at line 1： ORA/x7f00942： table or view does not exist Client B needs the dropped table and reports the problem to you. With reference to this scenario， which action should you take？（）
A、retrieve the table by using the flashback feature
B、restore all the data files from last Sunday’s backup， and then perform a timebased recovery
C、restore all the data files from last Sunday’s backup， and then perform a log sequence recovery
D、restore all the data files from last Sunday’s backup， and then perform a cancelbased recovery
E、restore from last Sunday’s backup only data files that belong to the tablespace in which the table was stored， and then perform a complete recovery
调整心态的“三把钥匙”的第二把是（）。
A、合作交流
B、进行政治和经济教育
C、以连为家——优化环境
D、经常性的思想教育
阅读下列资料，完成下列要求。材料农作物的生长离不开耕地，而耕地质量的高低，直接影响着农作物的产量。我国有相当一部分耕地质量低，农作物生长不良，成为农业低产区。下图为"我国某农业低产区的分布地区示意图"。上图所示地区为我国农业低产区之一，简述其主要成因。
简述国库单一账户的功能。
开立单位资信证明无须填写《单位银行账户业务约定/变更申请书》。（）
A、对
B、错
使用向导创建演示文稿时，可以随时单击【上一步】按钮返回到前面的对话框修改相应的设置。
A、对
B、错