设有教师表(教师号，教师名，工资，所在系)，现要建立统计每个系_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题填空题

设有教师表(教师号，教师名，工资，所在系)，现要建立统计每个系的教师平均工资的视图v_salary(dept,avg_salary)。请补全下列视图定义语句：
CREATE VIEW v_salary
AS
SELECT所在系As dept，______
FROM教师表
GROUP BY所在系

答案

参考答案：avg(工资)

解析：此题考查的是分组视图：带有聚集函数和group by子句的查询来定义视图，由于as子句中select语句的目标列平均工资是通过作用聚集函数得到的，所以creat view中必须明确定义组成V_salary视图的各个属性列名。

多项选择题

传染病的传染源包括

A．病人

B．病原携带者

C．受感染的动物

D．环境中的病原体

E．隐性感染者

完形填空

The cultures of the East and the West really distinguish each other a lot. This is because the culture systems are two ______ systems on the whole.
The ______ of the eastern cultures is mainly from two countries: China and India. Both of the two cultures are gestated（孕育） by rivers. In China, the mother river is the Yellow River _____ the Indian one is the Hindu River. These two cultures were developed for several thousand years and formed their own _____. Then in Dang Dynasty of China, the Chinese culture _____ went overseas to Japan, _____ into the Japanese society and shaped the Japanese culture nowadays. Though a bit different from the Chinese one, it belongs to the same ______.
When the two mother rivers gave birth to the eastern culture, another famous culture was ______ on the Mesopotamian Plain ---- the Mesopotamian Civilization. This civilization later on developed into the cultures of the Ancient Greece and Ancient Rome. And these two are well-known ______ the base of the European culture. Like the Chinese culture, the European one also ______ waters. When the colonists of England _____ in America, their culture went with them over the Atlantic Ocean. So the American culture doesn't _______ from the European one a lot.
At the same time, the difference of the language systems _______ the cultural differences. In the East, most languages belong to the pictographic language (see the picture below) while the Western languages are mostly based on the Latin system, for example, the one I’m using to write this paper.
Other factors like human race difference counts as well. But what’s more, ______ the far distance and the steep areas between the East and West, the two cultures seldom communicate until recent centuries. So they grew up totally in their own ways with almost no ______ from the other.

A．preservation

B．development

C．unfortunately

B．brought out

D．brought along

A．touched down

D．settled down

C．distinguish

B．results from

A．relationship

C．interference

D．familiarity