从被调查对象的母体中选出部分个体进行调查，并用个体特征推断出总体特征的调查称之为（）。

下列叙述正确的是（）。

A、进行打印预览时必须开启打印机

B、使用“文件”菜单中的“打开”命令可以打开一个已存在的.DOC文件

C、WORD2000可将正在编辑的文档另存为一个纯文本

D、WORD2000允许同时打开多个文件

Review the definition of the phone_list view. CHEATE OR REPLACE ALGORITHM=MERGE DEFINER= 'root'@localhost' SQL SECURITY DEFINER VIEW 'phone_list' AS SELECT e . id as id 'e . first_name AS 'first_name' 'e . last_name AS 'last_name' 'coalesce ( ph1.phone_no, ' – ') AS 'office_no' 'coalesce (ph2 .phone_no, ' – ') AS 'cell_no' FROM employees e LEFT JOIN employee_phone ph1 ON ph1.emp_id = e.id AND ph1.type = 'office' LEFT JOIN employee_phone ph2 ON ph2 .emp_id = e.id AND ph2 .type = 'mobile' The tables employees and employee_phone are InnoDB tables; all columns are used in this view. The contents of the phone_list view are as follows: Mysql> select * from phone_list; 1 row in set (0.00 sec) Which method can you use to change the cell_no value to '555-8888' for John Doe?（）

A、INSERT INTO employee_phone (emp_id, phone_no, type) VALUES (1, '555-8888','mobile')

B、UPDATE phone_list SET cell_name '555-8888' WHERE first_name= 'John' and last_name= 'Doe'

C、DELETE FROM phone_list WHERE first_name= 'John' and last_name= 'Doe'; INSERT INTO phone_list (first_name, last_name, office_no, cell_no) VALUES ('John' , 'Doe' , 'x1234' , '555-8888)

D、UPDATE employee_phone SET phone_no= '555-8888' where emp_id=1

Windows自带的可用于网络视频会议的软件是（）。

A、WinFax

B、Net2Fax

C、Iphone

D、Netmeeting

网络运营者，是指网络的所有者、管理者和网络服务提供者。

A、对

B、错

给同学王磊发邮件，以附件的方式发送本学期的课程表。王磊的Email地址是：wanglei@sohu.com主题为：最新课程表。正文内容为：王磊，你好！附件里是最新的课程表，请查看。将考生文件夹中的“课程表.doc”添加到邮件附件中，发送。