在VisualFoxPr0中，下面关于属性、方法和事件的叙述错误的是

A.属性用于描述对象的状态，方法用于表示对象的行为

B.基于同一个类产生的两个对象可以分别设置自己的属性值

C.事件代码也可以象方法一样被显示调用

D.在创建一个表单时，可以添加新的属性、方法和事件

Which of these appropriately describes the results of a manual SQL Tuning Advisor task?（）

A、A list of SQL statements and recommendations for tuning

B、A list of SQL statements that have been tuned by the Advisor, with before and after metrics

C、Graphs showing the actual performance improvement made by the Advisor after it implemented the recommended changes

D、All of the above

（7）已有查询文件queryone.qpr，要执行该查询文件可使用命令【7】。

View the Exhibit and note the contents of V$DIAG_INFO. Which statement is true about the ADR?（）

A、 The text alert log file will be available in Diag Trace

B、 A copy alert log file will be kept in Diag Incident for every incident.

C、 The XML version of the alert log file will be available in Diag Trace.

D、 An Automatic Database Diagnostic Management (ADDM) report is generated and stored in the Health Monitor whenever an incident occurs.

Which statement is true regarding virtual private catalogs?（）

A、A virtual private catalog owner can create a local stored script, and have read/write access to a global stored script.

B、The virtual private catalog owner cannot create and modify the stored scripts.

C、The set of views and synonyms that make up the virtual private catalog is stored in the schema of the RMAN recovery catalog owner.

D、To perform most of the RMAN operations, the virtual catalog owner must have the SYSDBA or SYSOPER privilege on the target database

（31 ） 查询尚未归还书的图书编号和借书日期，正确的 SQL 语句是

A ） SELECT 图书编号 , 借书日期 FROM 借阅 WHERE 还书日期 =" "

B ） SELECT 图书编号 , 借书日期 FROM 借阅 WHERE 还书日期 = NULL

C ） SELECT 图书编号 , 借书日期 FROM 借阅 WHERE 还书日期 IS NULL

D ） SELECT 图书编号 , 借书日期 FROM 借阅 WHERE 还书日期