问题 单项选择题

“年龄在18-25之间”这种约束是属于数据库当中的( )。

A.原子性措施

B.一致性措施

C.完整性措施

D.安全性措施

答案

参考答案:C

解析:数据库的完整性是指数据的正确性和相容性(如学生的学号必须惟一,性别只能是女或男等),数据库是否具备完整性关系到数据库系统能否真实反映现实世界,因此维护数据库的完整性是非常重要的。

阅读理解

阅读理解。

     It is a hot summer day, and you feel thirsty. A friend gives you a glass of cold lemonade. How do you

feel when you see the glass? Will you describe your feeling as happiness or as pleasure? I believe you will

say it is a feeling of pleasure. There is a connection between these two kinds of feelings, and sometimes

one causes the other, but they are not the same. Pleasure is more dependent on the five senses while

happiness is independent of them.

    When you are happy, little unpleasant events usually do not disturb you. When you are unhappy, you

feel as if everything is against you. You may compensate for it by eating chocolate and sweets because

this gives you pleasure;yet you stay unhappy. A person may smoke cigarettes because it gives him

pleasure, yet, this does not make him happier, especially if he knows the fact that it is not good for his

health.

    The physical world is always in a changing state. At each moment a new thing is being created ,

changed, transformed and then destroyed. This is the normal state of things and no one call change it.

If we stay still in a certain state, we are sure to experience unhappiness sooner or later. On the other

hand, if we adjust to the environment,  nothing can influence our moods. Then outer events have nothing

to do with our inner joy of mind.

    The room of the mind was filled with worry or fear. If you are free of thinking about them, the room

has been emptied,  and then you will see what is happening and experience it When your mind stays

quiet, you will see that happiness comes from the inside.

1.What does the underlined phrase "compensate for" in Paragraph 2 most probably mean?

A. to make a suitable payment for    

B. to let out your anger for

C. to provide with a balancing effect for

D. to solve the problems for

2. According to the passage, in which of the following situations can you feel happy?  

A. A friend gives you a glass of cold lemonade when you feel thirsty.

B. You eat chocolate and sweets when you feel as if everything is against you.

C. Smoke cigarettes even though you know the fact that it is not good for your health.

D. You are free from worry or fear when your mind stays quiet.

3.We can learn from the passage       .

A. happiness is more dependent on the five senses

B. pleasure sometimes arouses happiness

C. you feel happy when nothing around you changes in a certain state

D. you feel unhappy because you have to adjust to the environment

4.Which can be the best title for the passage?

A. Pleasure Leads To Happiness    

B. Happiness Changes Us

C. Happiness Is Within Us

D. Stay A Quiet Mind

问答题 简答题