问题 解答题

△ABC三个顶点坐标分别是A(4,3),B(3,1),C(1,2)。

(1)将△ABC向右平移1个单位,再向下平移2个单位,所得△A1B1C1的三个顶点坐标分别是什么?

(2)将△ABC三个顶点的横坐标都减去5,纵坐标不变,分别得到A2、B2、C2,依次连结A2、B2、C2各点,所得△A2B2C2与△ABC的大小、形状和位置上有什么关系?

(3)将△ABC三个顶点的纵坐标都减去5,横坐标不变,分别得到A3、B3、C3,依次连结A3、B3、C3各点,所得△A3B3C3与△ABC的大小、形状和位置上有什么关系?

答案

解:(1)A1(5,1),B1(4,-1),C1(2,0);

(2)△A2B2C2与△ABC的大小、形状完全相同,在位置上是把△ABC向左平移5个单位得到;

(3)△A3B3C3与△ABC的大小、形状完全相同,在位置上是把△ABC向下平移5个单位得到。

阅读理解

阅读理解。

     Hundreds of years ago, life was much harder than it is today. People didn't have modern machines. There

was no modern medicine, either.

     Life today had brought new problem. One of the biggest problems is pollution. Water pollution has made

our rivers and lakes dirty. It killed our fish and a our drinking water.    b    pollution makes us talk louder and

become angry more easily. Air pollution is the most serious kinds of pollution. It's hard to all the living things

in the world.

     Cars, planes and factories all pollute our air every day, (2) sometimes the polluted air is so thick that it is

like a quilt(被子) over a city. That kind of quilt is called smog.

     Many countries are making rules to fight pollution. Factories must now clean their water before it is poured

away, they mustn't blow dirty smoke into the air.

     We need to do many other things. We can put waste things in the dustbin and not throw it on the ground.

We can go to work by bus or with our friends in the same car.(3) 如果开车的人少了,空气污染就少了.

1. 在横线上填入适当的单词.

a. ________ b. ________(每空一词)

2. 将句子(2)译成汉语.

________________________________________________________

3. 将句子(3)译成英语.

________________________________________________________

4. 找出Dirty water must be stopped from dumping into the river.的同义句.

________________________________________________________________

5. 找出或写出能概括本文大意的句子.

________________________________________________________________

选择题