问题 选择题

在平面上具有整数坐标的点称为整点.若一线段的端点分别为(2,11),(11,14),则在此线段上(包括端点)的整点共有(  )

A.3个

B.4个

C.6个

D.8个

答案

设经过点(2,11)、(11,14)的直线方程y=ax+b(a≠0),则

11=2a+b
14=11a+b

解得,

a=
1
3
b=
31
3

∴所求的线段所在的直线方程为y=

1
3
x+
31
3

①当y=12时,x=5,即整点(5,12)在该线段上;

②当y=13时,x=8,即整点(8,13)在该线段上;

又∵端点(2,11)、(11,14)也是整点,

∴在此线段上(包括端点)的整点共有4个;

故选B.

阅读理解

Suppose you are a visitor in the land of Mongolia(蒙古), some friends ask you to eat with them. What kind of manners do they want you to have? They want you to give a loud “burp(打嗝)” after you finish eating. Burping shows that you like the food.

In some countries, if you give a loud burp, you are told to say “Excuse me, please.”

In many places people like to eat together. But in some parts of Polynesia(波利尼西亚)it is bad manners to be seen eating at all. People show good manners by turning their backs on others while they eat.

What are manners like in an East African town? People try not to see you. They are being polite. You may see a friend. He may not see you at all. If you are polite, you will sit down beside him. You will wait until he finishes what he is doing. Then he will talk to you.

Manners are different all over the world. But it is good to know that all manners begin in the same way. People need ways to show that they want to be friends.

小题1:In Mongolia, burping is a way to show that__________.

A.the host is very friendly with the visitors

B.one doesn’t want to eat anything at all

C.one enjoys the meal that is prepared by the host

D.one is not polite at table小题2: In some parts of Polynesia, to be polite while eating, one should____________.

A.eat as fast as possible

B.eat with his mouth full of food

C.turn his back on others

D.sit still without doing anything小题3:It is good manners for people in East African towns__________.

A.to sit down beside others and wait for them to talk

B.to say “hello” to others on the street

C.to try to talk to others when they are working

D.never to speak to anyone on the street小题4:We have good manners to show that we________.

A.are different from other

B.begin all manners in the same way

C.want to be friendly to other people

D.don’t want people to trouble us小题5:Which of the following is not true?

A.Manners are not the same in different countries.

B.It is good manners to give a burp when you’ve had enough in any place.

C.Sometimes manners are different in different places in the same country.

D.A person with good manners is liked by other people.

单项选择题