内容正文:
Unit 13
We’re trying to save the earth!
Section A 4a-4c
1.review the use of Present progressive, used to,
Passive voice, Present perfect and Modal verbs.
2. Learn and master new words and phrases.
学习目标
1.不同种类的污染
2. 河底
3. 把垃圾扔到河里
4. 在……中起作用
5. 在中国南部
6. 对……有害
7. 在……顶部
8. 海洋生态系统
different kinds of pollution
the bottom of the river
throw rubbish into the river
play a part in
in southern China
be harmful to
at the top of…
the ocean’s ecosystem
review
1. We’re trying to save the earth.
2. The river used to be so clean.
3. The air is badly polluted.
4. No scientific studies have shown that shark fins are good for health.
5. We should help save the sharks.
Present progressive
used to
Passive voice
Present perfect
Modal verbs
1.现在进行时: Present progressive
结构: be (am/is/are) + v.-ing形式
标志词:Look, Listen, now, right now…
e.g. Listen! The boy is singing.
定义:表示说话时(瞬间)正在进行的动作, 也表示目前或现阶段正在进行的动作,或说话者的强烈情感。
v.-ing形式(现在分词)的构成:
a. 一般情况下在动词词尾加-ing。
b. 以不发音的e结尾的动词,去掉e加-ing。
c. 以一个辅音字母结尾的重读闭音节,双写最后一个字母,再加-ing。
used to do sth. 表示过去常常做某事, 而现在往往不
了, 后接动词原形。
be used to doing sth. 表示习惯于做某事
e.g. I used to get up at six o’clock.
Joe is used to drinking a cup of coffee every morning.
2.used to do与be used to doing
3.被动语态:Passive voice
定义:表示主语是动作的承受者,即行为动作的对象的一种语态。
结构:be + 过去分词
e.g. A new school was built last year.
Our classroom is cleaned every day.
①一般现在时的被动语态:am/is/are + V-ed
②一般过去时的被动语态:was/were+ V-ed
③一般将来时的被动语态:will/shall+be+ V-ed
结构: have/has + 过去分词
标志词: already, yet, ever, never, just, before, once, twice, recently, so far, for+时间, since+时间点/从句。
定义: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持续下去的动作。
4.现在完成时: Present perfect
5. 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。
Let students say the the rules first and let others make up the points.
11
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