(共39张PPT)
Unit 13 We’re trying to save the earth!
Period(Three) Section A(grammar focus-4c)
版本:人教版九年级全册
Objectives
1. Learn curriculum words and useful expressions:
take part in, afford, turn off, reusable, pay for...
2. Summarize grammars about Present progressive,
used to, Passive voice, Present perfect, Modal verbs.
不同种类的污染
2. 河底
3. 把垃圾扔到河里
4. 在……中起作用
different kinds of pollution
the bottom of the river
throw rubbish into the river
play a part in
I. Check if you know these phrases.
5. 在中国南部
6. 对……有害
7. 在……顶部
8. 海洋生态系统
in southern China
be harmful to
at the top of…
the ocean’s ecosystem
Revision
II. Translation.
1. 这个方法不仅残酷还对环境有害。
This method is not only cruel, but also harmful to the environment.
2. 鲨鱼处于海洋食物链的顶部。
3. 许多人相信鱼翅对健康有好处。
Sharks are at the top of the food chain in the ocean’s ecosystem.
A lot of people believe that shark’s fins are good for health.
Grammar Focus
We’re trying to save the earth. Present progressive
The river used to be so clean. used to
The air is badly polluted. Passive voice
No scientific studies have shown that shark fins are good for health. Present perfect
We should help save the sharks. Modal verbs
一、现在进行时
表示现在正在进行或发生的动作，也表示现阶段或当前一段时间内正在进行的动作。
1.概念
2.基本结构
3. 标志词
now, at this time, these days, at the moment, listen, look等
be动词 (am/is/are) + 动词-ing形式
1. 我们现在正在河里游泳。
2. 听！琳达正在唱一首动听的歌。
3. 近来，鲨鱼正面临着艰难的生存环境。
We are swimming in the river now.
Listen! Linda is singing a beautiful song.
Sharks are facing hard living conditions these days.
翻译下列句子。
【拓展】
一些表示位置移动的动词，如 go, come, leave, arrive等，常用现在进行时表示将来。
例句：明天杰克将前往上海。
Jack is leaving for Shanghai tomorrow.
下列动词通常不用于现在进行时：
① 表示感觉或感情的动词，如smell, taste, seem,
like, love, wish, hope等；
② 表示记忆、理解或决定等的动词，如remember,
understand, decide, believe等﹔
③ 表示拥有或占有的动词，如have, belong, own等。
二、现在完成时
表示过去发生的动作对现在造成的影响或动作从过去某个时间开始，一直延续到现在（包括现在在内）并可能继续延续下去。
1.概念
2.基本结构
3. 标志词
recently, since... , for ... , in the past few years等
have/has +动词的过去分词
在现在完成时中，come, go, arrive, leave, buy 等非延续性动词不能与表示一段时间的时间状语连用。若与表示一段时间的时间状语连用，非延续性动词要转换成相应的延续性动词或短语。常见的词如下:
buy → have borrow → keep
join → be a member of finish → be over
die → be dead leave → be away
begin → be on fall asleep → be asleep open → be open
【拓展】
比较现在完成时与一般过去时：
现在
5年
过去
has been a teacher
将来
例句：他当老师5年了。（5年前到现在一直是老师）
He has been a teacher for 5 years.
现在
5年
过去
worked as a teacher
将来
例句：他当了5年老师。（现在不是老师了）
He worked as a teacher for 5 years.
三、被动语态
表示主语是谓语动词动作的承受者，其基本结构为“be动词 + 及物动词的过去分词”。
1. 概述
2. 构成
时态 被动语态的结构
am/is/are+及物动词的过去分词
was/were+及物动词的过去分词
will/shall be+及物动词的过去分词
一般现在时
一般过去时
一般将来时
am/is/are+being+及物动词的过去分词
现在进行时
have/has been十及物动词的过去分词
现在完成时
例句：所有的习题必须在放学前做完。
All the exercises must be finished before
school is over.
含情态动词的被动语态的结构为“情态动词+be+及物动词的过去分词”。
【拓展】
3. 主动语态转化为被动语态的步骤
将主动语态的宾语变成被动语态的主语。
第一步
第二步
第三步
把主动语态中的谓语动词变为“be动词+及物动词的过去分词”。
把主动语态中的主语变为被动句中介词
by的宾语。
4. 不能使用被动语态的情况
(1) 连系动词get, turn, seem, look, sound等后接形容
词作表语时；
(2) there be句型；
(3) 主动句中宾语是反身代词时；
(4) 不及物动词或词组，如：appear, disappear,
last, happen, take place, come about, break out等。
“used to十动词原形”，意为“过去常常……”，表示过去习惯性的动作或状态，现在已不存在。
1. 概述
四、used to的用法
2.句式结构
主语+used to+动词原形+其他.
主语+didn’t use to+动词原形+其他.
主语+usedn’t to+动词原形+其他.
Did+主语+use to+动词原形+其他
Used+主语+to+动词原形+其他
一般疑问句
反意疑问句
附加疑问句部分用“did/didn’t+主语”或“used/usedn’t+主语”
否定句
肯定句
表示说话人对所述动作或状态的态度或看法。情态动词无人称和数的变化，不能单独使用，其后接动词原形，构成谓语。否定形式的构成是在情态动词后面加not。
五、情态动词
1. 概念
2.基本用法
情态动词 意义及用法
意为“能；会”，表示能力，此时could 为can的过去式。
意为“可以”，表示请求、许可，此时could不是can的过去式，而是表示更委婉、客气的语气。
意为“可能”，can表示推测，常用于否定句或疑问句中。
can/could
(1) 情态动词can/could
(2) 情态动词may/might
意为“可以”，用于肯定句中表示许可；用于疑问句中表示请求。
意为“可能；也许”，表示推测，只能用于肯定句中。
(3) 情态动词must/have to
must和 have to意为“必须”，表示义务或责任。
must意为“一定；肯定”，表示推测，只能用于肯定句中。
(4) 情态动词should
意为“应该”，表示劝告、建议、命令等。
(5) 情态动词would
意为“愿意；将要”，表示意愿、请求等。
(6) 情态动词need
意为“需要；必要”，多用于否定句或疑问句中。以must开头的一般疑问句的否定回答常用needn’t或doesn’t/don ’t have to。
4a
Fill in the blanks with the correct forms of the verbs in brackets.
Joe: ______ you ever ______ (take) part in an
environmental project
Ken: Yes, I have. I _______ (help) with a Clean-Up Day
last year. It was __________ (consider) the biggest
clean-up project this city ____ ever ____(have).
Joe: How many people _____ (take) part
Have
taken
helped
considered
take part in意为“参加”。
【辨析】take part in, join与 join in
take part in指参加会议或群众性活动等，往往指参加者持有积极的态度，并在其中发挥一定的作用。
join指加入某个党派、组织或团体等，成为其中的一员。
join in多指参加小规模的活动，如球赛、游戏等。
had
had
took
Ken: I _____ (think) more than 1,000 people _____
(come) to help out.
Joe: That’s fantastic! I guess everyone in this city is
_______ (try) to improve the environment.
Ken: Yes, we can’t afford to _____ (wait) any longer
to take action!
think
came
trying
wait
afford sth. 买得起某物
afford to do sth.有能力做某事；负担得起做某事
take action意为“采取行动”。
take action to do sth.意为“采取行动做某事”。
4b
can
would
could
have to
should
must
may/might
People __________ think that big things _______________ be done to save the earth. Many forget that saving the earth begins with small things. For example, you ______________ save electricity by turning off the lights when you leave a room. You _______________ also use reusable bags instead of plastic bags.
may/might
must/have to/should
can/could/should
can/could/should
Fill in the blanks with the appropriate modal verbs from the box.
I think it’s a great idea that you now ______ pay for plastic bags in some stores. And instead of driving to school or work, you _______________ ride your bike or walk. If it’s far, you _________ take the bus. All these small things ________ add up and become big things that _________________ improve the environment. Let’s take action now!
have to
can/could
can/could
would/can/could
can/could/should
4c
Make a list of things that people can do to help the environment and discuss your list with your partner.
use public transportation (n.交通运输);
turn off the lights when you leave a room; use reusable bags instead of plastic bags; ride your bike or walk to school or work; stop using paper napkins (n. 餐巾纸);recycle books and paper…
Discussion
I think that everyone should use public transportation.
I disagree. It’s difficult for parents with young children to use public transportation…
Language points
1. We can’t afford to wait any longer to take action!
afford v. 承担得起;买得起；提供, 给予
常与can, be able to连用, 后面可接名词、代词、不定式等(多用于否定句或疑问句)。
afford sth. 买得起/承受得起某物
afford to do sth. 有能力做某事/负担得起做某事
e.g. Can you afford the mobile phone
We can’t afford to pay such a price.
afford & buy
afford侧重“有经济能力买”，而buy则侧重“购买(这一行为)”。
表示“我买不起……”可以说I can’t afford ...，但不能说I can’t buy ...。
2. …save electricity by turning off the lights when you leave a room.
turn off 关掉
【翻译】
睡觉前请关掉电视。
Please turn the television off before you go to bed.
turn on 打开, 发动 turn around 转身
turn up 调高(音量) turn down 调低; 拒绝
turn into 变成; 进入 turn over 移交
【拓展】turn相关短语
3. attend，join& take part in
它们都可表示“参加”，区别如下：
◆attend是正式用语，侧重指参加会议、婚礼、典礼，去上课、上学、听报告等。
◆join侧重指加入某个党派、团体组织等，成为其成员之一；join 也可以表示和某人一起做某事，其结构为：join sb. in (doing) sth.。
◆take part in侧重指参加群众性活动等，着
重说明句子主语参加该项活动并在活动中
发挥作用。
Exercise
Ⅰ. 适当形式填空
1. When Tom ___________ (ask) why he
was late for school, he just kept silent.
2. In the past few years, great changes
____________ (take) place in our town.
3. Someone ___________ (knock) at the door.
Can you open it
4. Wow! You ____________ (cook) dinner!
Let’s eat now.
was asked
have taken
is knocking
have cooked
Ⅱ. 选词填空 used to, mustn’t, can’t, should,
1. Children _______ sit in the front seat of a
car. It’s too dangerous.
2. —Is that girl Susan
—It _______ be her. She has gone to
Beijing.
3. My father _______ be a doctor, but now he
works as a teacher.
4. —Many people play with mobile phones all
day instead of reading books.
—That’s too bad. Everyone _______ be a
book lover. Reading is more enjoyable.
mustn’t
can’t
used to
should
Homework
Preview the new words and
expressions in Section B.
谢谢
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Unit 13 We’re trying to save the earth!
Section A (Grammar focus-4c)练习
一. 用can，may，must，need或have to的适当形式填空。
1. You ____ return the book to the library on time.
2. I ____ find the way to the hospital. ____ you show me the way
3. —____ I finish the work right now
—No, you ____. You ____ do it later.
4. He said he ____ come tonight.
5. Her mother was ill. She ____ stay at home and look after her.
6. It's time for class. You ____ stop playing football or you ____ be late for class.
7. The cloud is lifting，so it ____ be a rainy day tomorrow.
8. The desk is not dirty. You ____ clean it.
9. —What is your mother going to do this Saturday
—I'm not sure. She ____ go to see my grandmother.
10. If the traffic light is red，you ____ cross the road. It's dangerous.
二. 用括号内所给单词的适当形式填空。
1. We don't need ____ (work) today.
2. He doesn't dare ____ (break) his promise.
3. Some students are used to ____ (ask) their parents for help when they meet trouble.
4. There used ____ (be) a quiet village here.
5. You will be used to ____ (live) in the countryside.
6. All of us know that cotton can be used ____ (make) cloth.
7. You used ____ (go) to school by bike，didn't you
三. 根据汉语意思完成句子，每空一词。
1. 这本书一定是汤姆的，他的名字在封面上。
This book ____ ____ Tom's. His name is on the cover.
2. 他可能被一个五岁的小男孩愚弄了吗？
____ ____ ____ true that he was fooled by a five-year-old boy
3. 你的车需要维修了。
Your car ____ ____.
4. 这种小刀是用来切东西的。
This kind of knife ____ ____ ____ ____ things.
5. 我年轻的时候常常打篮球。
I ____ ____ ____ basketball when I was young.
6. 他过去常花很多时间玩电脑游戏吗？
____ ____ ____ ____ ____ much time playing computer games
四、根据句意及首字母或汉语提示填 写单词。
1. The house is really expensive. I can't a_____ it.
2. How much did you p_____ for the computer
3. Remember to turn o_____ the light when you leave the room.
4. What do you think of the t_____ (交通运输) in your city
5. This kind of material is r_____ (可重复使用的). Don't throw it.
五、单项选择。
1. —Why don't you buy the computer
—It's too expensive. I can't ________ it.
A. afford B. sell
C. borrow D. keep
2. —Would you like to ________ us in this topic
—Yes，I'd like to.
A. join B. join in
C. take part in D. attend
3. Our government has to do something ________ our environment.
A. protect B. protected
C. protecting D. to protect
4. Nobody is in the room. Please go and ________ the light.
A. turn on B. turn off
C. turn down D. turn up
5. —How much is the ticket to Central Park
—A one-way ticket ________ $40，and you can ________ another $20 for a round-trip.
A. costs；pay B. cost；spend
C. pay；spend D. spends；pay
六. 根据句意，从方框中选择恰当的短语填空，有的需要变换形式。
pay for, take part in, turn off, take action, add up
1. In order to keep those little children safe, he _______ electricity and gas just now.
2. It's my treat today. I'll _________ the meal.
3. In the end, he __________ the project and worked with us together.
4. We must ___________ to deal with the problem before it spreads to other places.
5. _________ all these figures (数字) and you will get the right answer.
参考答案：
一、1. must 2. can't; Could; 3. Must; needn’t; may/can 4. couldn't 5. had to 6. must; may
7. can't 8. needn't 9. may/might 10. mustn't
二、1. to work 2. to break 3. asking
4、to be 5. living 6. to make 7. to go
三、1. must be 2. Can it be 4. needs repairing
4、is used to cut 5、 used to play 6、Did he use to spend
四、1.afford 2. Pay 3. off 4. transportation 5. reusable
五、1-5AADBA
六. 1. turned off 2. pay for 3. took part in 4. take action 5. Add up
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