Which view should a user query to display the columns associated with the constraints on a table owned by the user? （）

A、USER_CONSTRAINTS

B、USER_OBJECTS

C、ALL_CONSTRAINTS

D、USER_CONS_COLUMNS

E、USER_COLUMNS

The ORDERS table has these columns: ORDER_ID NUMBER(4) NOT NULL CUSTOMER_ID NUMBER(12) NOT NULL ORDER_TOTAL NUMBER(10,2) The ORDERS table tracks the Order number, the order total, and the customer to whom the Order belongs. Which two statements retrieve orders with an inclusive total that ranges between 100.00 and 2000.00 dollars? （）

SELECT customer_id, order_id, order_total FROM orders RANGE ON order _ total (100 AND 2000) INCLUSIVE;

SELECT customer_id, order_id, order_total FROM orders HAVING order _ total BETWEEN 100 and 2000;

SELECT customer_id, order_id, order_total FROM orders WHERE order _ total BETWEEN 100 and 2000;

SELECT customer_id, order_id, order_total FROM orders WHERE order_total>= 100 and <= 2000;

SELECT customer_id, order_id, order_total FROM orders WHERE order_total>= 100 and order_total <= 2000;

The user HR owns the EMP table. The user HR grants privileges to the user SCOTT by using this command：  SQL> GRANT SELECT，INSERT，UPDATE ON emp TO scott WITH GRANT OPTION； The user SCOTT executes this command to grant privileges to the user JIM： SQL> GRANT SELECT，INSERT，UPDATE ON hr.emp TO jim；  Now， the user HR decides to revoke privileges from JIM using this command： SQL> REVOKE SELECT，INSERT，UPDATE ON emp FROM jim； Which statement is true after HR issues the REVOKE command（）

A、The command fails because SCOTT still has privileges.

B、The command succeeds and privileges are revoked from JIM.

C、The command fails because HR cannot revoke the privileges from JIM.

D、The command succeeds and only HR has the privilege to perform the SELECT， INSERT， and UPDATEoperations on the EMP table.

Windows系统中的磁盘碎片整理程序__（1）__，这样使系统__（2）__。空白（1）处应选择（）

A、仅将卷上的可用空间合并，使其成为连续的区域

B、只能使每个文件占用卷上连续的磁盘空间，合并卷上的可用空间

C、只能使每个文件夹占用卷上连续的磁盘空间，合并卷上的可用空间

D、使每个文件和文件夹占用卷上连续的磁盘空间，合并卷上的可用空间

Which of the following connector types is used on CAT5e cable?（）

A、RJ-45

B、ST

C、RJ-11

D、BNC

线缆接头、接地卡做防水抱扎，要按顺序紧密缠绕绝缘胶带和防水胶带（采用3X3处理，即3层绝缘+3层防水+3层绝缘），馈线抱扎后擦启用扎带将抱扎处固定后涂上硅胶。（）

A、对

B、错