解： （1）A（0，2）， B（，1）（2）（3）如图1，可求得抛物线的顶点D（）设直线BD的关系式为， 将点B、D的坐标代入，求得， BD的关系式为设直线BD和x 轴交点为E，则点E（，0），CE= DBC的面积为（4）如图2，过点作轴于点M，过点B作轴于点N，过点作轴于点P在RtABM与RtBAN中， AB=AB， ABM=BAN=90-BAM， RtABMRtBAN BM=AN=1，AM=BN=3， B（1，）同理ACPCAO，CP=OA=2，AP=OC=1，可得点C（2，1）；将点B、C的坐标代入，可知点B、C在抛物线上（事实上，点P与点N重合）中考英语书面表达背诵范文 （二） 一、 Great changes in my hometown More than twenty years ago, my hometown was just asmall , old and poor town. Most of people were farmers. There were fewfactories. The people didnt have enough food to eat and wore old clothes. Theyhad a hard life . Great changes have taken place in the past twentyyears . The people have found a lot of ways of making money . Now there aremany tall buildings . They are very beautiful . Roads are wide and clean .People can take buses or drive their own cars to go to work . Many people havecell phones and personal computers. Peoples living conditions have improved alot . Thanks to the governments efforts . my hometown is becoming more andmore beautiful . 二、 Save the earth How to protect the environment has become one of thebiggest problems in the world . Its our duty to protect our environment . No matterwhere we live , we should do something to keep our neighborhood clean and tidy. We can collect waste paper or other waste things for recycling. We shouldplant more trees and we should prevent those factories from pouring waste waterinto rivers, lakes and fields. Weshouldnt leave rubbish everywhere and spit in public places . We mustnt pickthe flowers or step on the grass in public. If everyone tries his best toprotect the environment , the world will become much more beautiful and ourlife will be better and better . 三、 Improve our environment Good environment can make people feel happy. Toimprove the environment means to qualify our life . What should we do toimprove our environment ? We should plant more trees . And we should preventthose factories from pouring waste water into rivers , lakes and fields .Whenever we see litter on the ground , we should pick it up and throw it into adustbin . Dont spit in public places . Dont draw on public walls . Its ourduty to keep our earth clean and tidy . 四、 Pollution around us In recent years our life isbecoming better and better. But our environment is becoming worse and worse. Itsvery bad for our life. Now many people have air-conditioners and cars, theyproduce (give off ) waste gas. More and more trees are being cut down. Thereare so much sand on the earth (leaving only sand ) . We often see factoriespour waste into rivers or lakes. Water in the river is quite dirty. We haventenough clean water to drink in cities. Now we are in danger. Its verynecessary and important to protect the environment well. I think if everyonetries his best to protect the environment, the world will become much morebeautiful , and our life will be better and better . 五、 Make our world more beautiful ! Protecting theenvironment is becoming more and more important to humans . Its our duty totake care of the nature around us . Animals and plants are our best friends .,and we should share the world with them . We shouldnt kill wild animals , andwe must protect forests because they are animals home . We must plant moretrees and grass , they can make the world greener . The more beautiful theworld is, the happier lives we will have . Lets do our best to make the worldbeautiful. 六、 Keep our school clean We are studying in this school. It is our duty to keepit clean and tidy. It is not good to spit in public places, such as in thelibrary, in the class. We shouldnt leave rubbish here and there. Dont drawpictures on the wall, they influence the look of our school . We should keepthe classroom clean and tidy. And we should do some cleaning often. If everyonetries his best to do something useful for our school, Im sure our school willbe more beautiful . 七、 My country life I like to live in the countryside. I live in a smallvillage. There is a river near it. Lots of trees are around my house. I can seea lot of farms and birds. There is less noise. The air here is cleaner andfresher. There are fewer cars. I read aloud early in the morning. When it isgetting dark, the moon is bright in the sky. Its very quiet . What a niceplace I live in ! 八、 How to learn English well As we know , English has become an internationallanguage. It is more popular than any other language in China . English iswidely spoken in the world and it is the most useful language around the world. But how to learn it well ? The best way is to use it all the time . If we cantalk in English , think in English we can learn it well . At school , we shouldlearn to hear , speak, read and write carefully . We should spend enough timein practicing English . If we keep on working hard at English , w