Unit 13 We're trying to save the earth! sectionA-4a-4d(共30张PPT)

(共30张PPT)
Unit13 We're trying to save the earth! Section A grammar 4a-4b
To review the key structures: present progressive tense, present perfect tense, passive voice
Learning Objectives
Mark and Tony didn't go swimming in the river because the river _____ badly polluted. It was really dirty now. People are ________ litter into the river, and factories ____ also _______ waste into the river. In fact, it ________ be so clean, and it has always _____ the nicest river in this town. Tony think that they ______write to the government and let the government close down the factories. Mark advise that everyone in this town _______ help to clean up the river not just the government.
Fill in the blanks according to the conversation in 1b.
was
throwing
are
putting
used to
been
should
should
Mark and Tony didn't go swimming in the river because the river _____ badly polluted. It was really dirty now. People are ________ litter into the river, and factories ____ also _______ waste into the river. In fact, it ________ be so clean, and it has always _____ the nicest river in this town. Tony think that they ______write to the government and let the government close down the factories. Mark advise that everyone in this town _______ help to clean up the river not just the government.
was
throwing
are
putting
used to
been
should
should
Find Passive voice.
Mark and Tony didn't go swimming in the river because the river _____ badly polluted. It was really dirty now. People are ________ litter into the river, and factories ____ also _______ waste into the river. In fact, it ________ be so clean, and it has always _____ the nicest river in this town. Tony think that they ______write to the government and let the government close down the factories. Mark advise that everyone in this town _______ help to clean up the river not just the government.
was
throwing
are
putting
used to
been
should
should
Find present progressive.
Mark and Tony didn't go swimming in the river because the river _____ badly polluted. It was really dirty now. People are ________ litter into the river, and factories ____ also _______ waste into the river. In fact, it ________ be so clean, and it has always _____ the nicest river in this town. Tony think that they ______write to the government and let the government close down the factories. Mark advise that everyone in this town _______ help to clean up the river not just the government.
was
throwing
are
putting
used to
been
should
should
Find used to pattern.
Mark and Tony didn't go swimming in the river because the river _____ badly polluted. It was really dirty now. People are ________ litter into the river, and factories ____ also _______ waste into the river. In fact, it ________ be so clean, and it has always _____ the nicest river in this town. Tony think that they ______write to the government and let the government close down the factories. Mark advise that everyone in this town _______ help to clean up the river not just the government.
was
throwing
are
putting
used to
been
should
should
Find Present perfect.
Mark and Tony didn't go swimming in the river because the river _____ badly polluted. It was really dirty now. People are ________ litter into the river, and factories ____ also _______ waste into the river. In fact, it ________ be so clean, and it has always _____ the nicest river in this town. Tony think that they ______write to the government and let the government close down the factories. Mark advise that everyone in this town _______ help to clean up the river not just the government.
was
throwing
are
putting
used to
been
should
should
Find Model verbs.
Now people are taking actions to save wild animals. Let's join them.
We're trying to save the earth!
[探究]
[用法] 现在进行时用来描述现在正在发生的动作。
该时态的结构是
He ________ ________ ________ his keys now.
他现在正在找钥匙。
[标志] 常见的标志有
如：Look! A policeman _____ ________ towards us.
看！一名警察正向我们跑过来。
“be(am/is/are)＋现在分词”
is looking for
is running
now, at the moment 等词或短语，
以及“Look！”或“Listen！”等警示语。
What are they doing
Many have heard of shark fin soup.
No scientific studies have shown that shark fins are good for health.
[探究]
[用法] 现在完成时用来表示动作已经完成，但对现在造成
影响，或者表示从过去某一时间开始一直延续到现
在并还可能继续延续下去。
该时态的结构是
[标志] 常见的标志有
“have/has＋过去分词”
already, yet, just, never, so far,
up till now, since+时间点/从句， for+时间段等。
活学活用
They ________ ________ the classroom.
他们打扫过教室了。
He ________ ________ here since 2008.
自从2008年以来，他一直住在这儿。
He has ________ finished the work.
他已经完成那项工作了。
They have lived in Beijing _______ _______ ______.
他们已经在北京住了十年了。
have cleaned
has lived
already
for ten years
The air is badly polluted.
It was considered the biggest clean up project this city has ever had.
[探究]
[构成] 被动语态由“________＋及物动词的_________”构
成，其中人称、数和时态的变化是通过be动词的变
化表现出来的。
[注意] (1)只有及物动词或相当于及物动词的短语才有被
动语态，不及物动词、系动词没有被动语态。
1. Our classroom ________ ________ every day.
我们每天打扫教室。
2. The light ________ ________ ________ off.
应该把灯关掉。
be 过去分词
is cleaned
should be turned
[探究]
[注意] (2)有些使役动词和感官动词在主动语态中接不带to
的动词不定式作宾语补足语，但改为被动语态时，
不定式符号to必须补上。
I often hear her sing the song in her room.
→She is often ________ ________ ________ the
song in her room.
heard to sing
The river is dirty.
But it used to be so clean!
[探究]
[用法] 1. used to表示“过去经常；以前常常”，用来描述过
去经常发生的动作或存在的状态。如
There used to be a small pond in the village.
那个村庄里以前有一个小池塘。
2. used to do结构的否定句、疑问句要借助于助动词
_______。如：
He didn't use to play basketball.
他过去不经常打篮球。
did
活学活用
1. She _____ _____ _____ tennis with her classmates.
她以前经常和她的同班同学打网球。
2. ________ you ________ to take a walk after supper
你过去晚饭后经常散步吗？
3. She used to wear glasses, ______ she
她过去常常戴眼镜，不是吗？
used to play
Did use
did
We should help save the sharks.
So together, our actions can make a difference and lead to a better future!
[探究]
[用法] 情态动词是表示能力、义务、允诺、猜测等的动词。
在初中阶段我们学到的情态动词及其用法见下表：
表“能力”或“许可”。可以用在否定句中表推测。
must
can
表“必须”，语气较为强烈。可以用在肯定句中表推测，肯定的语气很强。
意为“应该”，否定式是 shouldn't，意为“不应该”。
need
should
could
may
could既是can的过去式，本身也是情态动词，语气较为委婉。
表“许可”，语气较委婉。可以用在肯定句中表推测，肯定语气小于must。
可以作情态动词，还可以作实义动词。need to do sth.意为“需要做某事”。
活学活用
1. 我们不能在教室里吃东西。
2. 首先你必须完成作业。
3. 他现在不可能在家。
4. 她一定知道这个问题的答案。
We can’t eat in the classroom.
You must finish your homework first.
He can’t be at home now.
She must know the answer to this question.
Fill in the blanks with the correct forms of the verbs in brackets.
4a
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
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
Fill in the blanks with the appropriate modal verbs from the box.
4b
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.
can
would
could
have to
should
must
may/might
may/might
must/have to/should
can/could/should
can/could/should
Make a list of things that people can do to help the environment and discuss your list with your partner.
4c
I think that everyone should use public transportation.
I disagree. It’s difficult for
parents with young children to use public transportation…