问题 单项选择题

下列实体类型的联系中,属于多对多联系的是( )。

A.学生与课程之间的联系

B.学校与教师之间的联系

C.商品条形码与商品之间的联系

D.班级与班长之间的联系

答案

参考答案:A

解析: 实体之间的联系分为:一对一、一对多和多对多。因为在每一个学生都能学习很多的课程,所以学生和课程之间是多对多的联系。

阅读理解

It is thought that crying is hardly an activity encouraged by society. Tear, whether they are of sorrow, anger, or joy, typically make Americans feel uncomfortable and embarrassed. The shedder of tears (落泪者) is likely to apologize, even when a great tragedy was the cause. The observer of tears is likely to do everything possible to put an end to the emotional tears. But judging from recent studies of crying behavior, both those responses to tears are often inappropriate and may even be counterproductive (适得其反).

Humans are the only animals clearly known to shed emotional tears. Since evolution has given rise to few purposeless physiological responses, it is logical to assume that crying has one or more functions that enhance (increase) survival.

Although some observers have suggested that crying is a way to ask for assistance form others (as a crying baby might from its mother), the shedding of tears is hardly necessary to get help. Vocal cries would have been quite enough, more likely than tears to gain attention. So, it appears, there must be something special about tears themselves.

Indeed, the new studies suggest that emotional tears may play a direct role in alleviating stress, University of Minnesota researchers who are studying the chemical composition of tears have recently isolated two important chemicals from emotional tears. Both chemicals are found only in tears that are shed in response to emotion. Tears shed because of exposure to cut onion would contain no such substance.

Other researchers are investigating the usefulness of tears as a means of diagnosing human ills and monitoring drugs. At Tulane University’s Teat Analysis Laboratory Dr. Peter Kastl and his colleagues report that they can use tears to detect drug abuse, to study the causes of “dry eye” syndrome(综合症)and the effects of eye surgery, and perhaps even to measure exposure to environmental pollutants.

小题1:What does the phrase “both those responses” in Paragraph 1 refer to ?

A.Crying out of sorrow and shedding tears for happiness.

B.The embarrassment and unpleasant sensation of the observers.

C.The tear shedder’s apology and the observer’s effort to stop the crying.

D.Linking illness with crying and finding the chemical composition of tears.小题2:From the passage we can infer that        .

A.it is unnatural for people to shed tears

B.we can reduce our stress by shedding tears

C.shedders of tears can’t get help by crying loudly

D.unlike animals, humans can shed tears for survival小题3:What does the passage mainly talk about?

A.Roles of emotional tears.

B.functions of shedding tears.

C.Unwelcome shedders of tears.

D.Research on the effects of tears.

判断题