问题 填空题

假设订货管理数据库中有3个表,仓库.DBF、职工.DBF和订购单.DBF,它们的结构分别如下:
仓库表(仓库号C(4),城市C(10),面积I(4))
职工表(仓库号C(4),职工号C(4),工资Y)
订购单表(职工号C(4),供应商号C(3),订购单号C(6),订购日期D,总金额Y)
检索工资多于1200元的职工号,请对下面的SQL语句填空。
SELECT职工号;
FROM (10)
WHERE工资>1200
检索在仓库"E23”或"W32”工作,并且工资少于2000元的职工号,请对下面的SQL语句填空。
SELECT 职工号 FROM 职工;
WHERE 工资<2000 (11)
检索工资大于2000元的职工所管理的仓库的平均面积,及其中的最大面积和最小面积。请对下面的SQL语句填空。
SELECT (12) ,MAX(面积),MIN(面积);
FROM 仓库 WHERE 仓库号 (13)
(SELECT (14) FROM 职工 WHERE 工资>=2000)
检索每个仓库至少有3名职工的工资总额。请对下面的SQL语句填空。
SELECT 仓库号,COUNT(*),SUM(工资)FROM 职工;
GROUP BY 仓库号;
(15) >=3

答案

参考答案:AVG(面积)

单项选择题
阅读理解

阅读理解。

     Being able to multitask-doing several things at the same time-is considered a welcome skill by most people.

But if we consider the situation of the young people aged from eight to eighteen, we should think again.

     What we often see nowadays is that young people juggle an ever larger number of electronic devices (电子

产品) as they study. While working, they also surf on the Internet, send out emails, answer the telephone and

listen to music on their iPods. In a sense, they are spending a significant amount of time in fruitless efforts as

they multitask.

     Multitasking is even changing the relationship between family members. As young people give so much

attention to their own worlds, they seem to have no time to spend with the other people around them. They

can no longer greet family members when they enter the house, nor can they eat at the family table.

     Multitasking also affects young people's performance at university and in the workplace. When asked about

their opinion of the effect of modern gadgets (器具) on their performance of tasks, many young people gave

a positive response (反应). However, the response from the worlds of education and business was not quite

as positive. Educators feel that multitasking by children has a serious effect on later development of study skills.

They believe that many college students now need help to improve their study skills. Similarly, employers feel

that young people entering the job market need to be taught all over again, as modern gadgets have made it

unnecessary for them to learn special skills to do their work.

1. What does the underlined word "juggle" in Paragraph 2 most probably mean?

A. Want to buy.

B. Take the place of.

C. Use at the same time.

D. Seek for information from.

2. In Paragraph 3, the author points out that _____.

A. family members do not eat at the family table

B. family member do not greet each other

C. young people live happily in their families

D. young people seldom talk with their family members

3. What is the main idea of the last paragraph?

A. Multitasking is harmful to young people's development.

B. Young people benefit a lot from modern gadgets.

C. Multitasking is an important skill to young people.

D. Young people must learn skills for future jobs.

4. The author develops the passage mainly by _____.

A. providing typical examples

B. following the natural time order

C. comparing opinions from different fields

D. presenting a cause and analyzing its effects