有三个关系R、S和T如下：其中关系T由关系R和S通过某种操作得到，该操作为（　　）。

A、选择

B、投影

C、交

D、并

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.

在powerpoint2010中提供了左对齐，右对齐，（），（），（）5种对齐方式。

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;

人（手）孔型式包括（）。

A、直通型

B、斜通型

C、三通型

D、四通型

提升项目团队能力的途径主要有（）。

A、组织团队学习

B、培训

C、合理授权

D、标杆超越

E、团队共享奖励