Unit 13 We’re trying to save the earth!Section A (Grammar focus—4b)【学习目标】1. 学习并掌握新词汇：reusable, afford, transportation2. 学习并会用以下常用表达：try to do sth., used to do sth., is/are doing, be considered,take part in; play a part in doing sth., help with, help out, turn off, instead of, pay for, add up, afford to do sth., not …any longer, take action, It’s difficult for sb.to do sth.3. 学习并掌握下列句型：1) We’re trying to save the earth.2) The river used to be so clean.3) It was considered the nicest river in town.4) The air has become really polluted.5) We should help save the sharks.6) Everyone should play a part in keeping the city clean.7) You can save electricity by turning off the lights when you leave a room.8) We cannot afford to wait any longer before taking action!9) It’s difficult for parents with young children to use public transportation【重点难点】正确使用本课语法要点。
【新知预习】根据句意和首字母提示完成单词。
1. It was c________ the nicest river in town.2. You can also use paper or r_______ bags instead of plastic bags.3. We cannot a_______ to wait any longer before taking action!4. We think that everyone should use public t________.5. I guess everyone in this city is trying to improve the e_________.【课堂探究】一、现在进行时：概念：表示现阶段或说话时正在进行的动作及行为。
时间状语：now, at this time, these days, etc. 基本结构：am/is/are+doing 否定形式：am/is/are+not+doing. 一般疑问句：把be动词放于句首。
二、used to的意思是“过去经常”，其中的to是不定式符号，不是介词，所以其后接动词原形(不接动名词)。
三、现在完成时：概念：过去发生或已经完成的动作对现在造成的影响或结果，或从过去已经开始，持续到现在的动作或状态。
时间状语：recently, lately, since…for…,in the past few years, etc. 基本结构：have/has + done 否定形式：have/has + not +done.四、被动语态：概念：当主语为动作的承受者时，谓语要用被动语态。
基本机构：“助动词be＋及物动词的过去分词”构成。
含有情态动词的被动语态由“情态动词＋be＋及物动词的过去分词”构成。
助动词be有人称、数和时态的变化，其变化规则与be作为连系动词时完全一样。
五、情态动词should后接动词原形。
（1）表示“应该，应当” You should help your mother with the housework. 你应该帮你母亲做家务。
（2）表示“可能，该(=will probably) ”He should arrive soon他可能很快就到了。
【达标练习】I. 单项选择。
( ) 1. We’re trying ______ the earth.A. to saveB. savingC. savedD. be saved( ) 2. My good friend becomes good at __________English every day.A. speakB. speakingC. speaksD. to speak( ) 3. I _________ take dance lessons, but I don’t anymore now.A. used toB. usedC. usingD. to use to( ) 4. It was ________the nicest river in town.A. consideringB. consideredC. have consideredD. to be considered ( ) 5. When it comes to ________ the earth, people may think that big things should be done.A. saveB. be savedC. savedD. savingII. 用所给单词的适当形式填空。
1. —_______ you ever_______ (take) part in an environmental project?—Yes, I have.2. I’ve become much _______ (good) at speaking English.3. The air has become really_______ (pollute).4. Everyone should _______ (play) a part in keeping the city clean.5. I guess everyone in this city is_______ (try) to improve the environment.6. You can save electricity by _______ (turn) off the lights when you leave a room.7. We cannot afford to_______ (wait) any longer before taking action!8. I_______ (help) with a Clean-Up Day last year.III. 根据所给汉语完成英语句子。
1. 这条河过去很干净。
The river _______ _______ _______ so clean.2. 我们应该帮助拯救鲨鱼。
We should _______ _______ the sharks.3. 然而，很多人忘记了拯救地球从小事做起。
However, many forget that saving the earth_______ _______ small things.4. 在很多商店，你不得不付塑料袋的费用In some stores, you now have to _______ _______ plastic bags.5. 我们认为每个人都应该使用公共交通工具。
We think that everyone should use ________ ________.6. 所有这些小的事情加起来变成能改善环境的大的事情。
All these small things can _______ _______ and become big things that would ________ _______ ________.7. 我们已经看到环境方面的很多变化。
We ________ _________ _________ _________ in the environment.8. 空气污染变得越来越糟糕了。
The air pollution is _________ _________ _________ _________.9. 这条河被工厂污染了。
The river_________ _________ by factories.10.人们应该多乘坐公共交通工具。
People should________ ________ _________ more.●Time, Time again, I ask myself （请写出这节课你的收获，完成下面的反思）【学后反思】九年级英语第13单元学案参考答案及解析第三课时【新知预习】1. considered2. reusable3. afford4. transportation5. environment （解析略）【达标练习】I.1.A try to do sth. 尽力干某事。
2.B be good at doing sth擅长做某事。
3.A used to do sth.过去常常干某事。
4.B 主语和谓语动词之间是被动关系。
5.D 介词后边跟动名词。
II.1.Have taken 根据回答，确定用现在完成时态。
2. better much修饰比较级的考察。
3. polluted 被污染。
4. play 情态动词后加动词原形。
5. trying 现在进行时态的考察。
6. turning 介词后跟动词的现在分词形式。
7. wait afford to do 支付做某事的花费。
8.helped 由last year，可知用一般过去时。
III. 1. used to be 2. help save 3. begins with 4. pay for 5. public transportation 6. add up; improve the environment 7. have seen many changes 8. getting worse and worse9. is polluted 10. take public transportation。
