九年级英语下册Unit 13《We’re trying to save the earth》Section A（3a-3b）课件（共46张PPT）

(共46张PPT)
Period 2 Section A (3a-3b)
Unit 13 We’re trying to save the earth!
Is it important for us to save the sharks Why
3a Read the passage about sharks and complete the fact sheet below.
Many have heard of shark fin/f n/ soup. But do you realize that you’re killing a whole shark each time you enjoy a bowl of shark fin soup
Save the Sharks!
杜绝恶劣的饮食习惯，保护海洋环境。
When people catch sharks, they cut off their fins and throw the shark back into the ocean. This is not only cruel, but also harmful to the environment. ① Without a fin, a shark can no longer swim and slowly dies. ② Sharks are at the top of the food chain in the ocean’s ecosystem. ③ If their numbers drop too low, it will bring danger to all ocean life.
Many believe that sharks can never be endangered because they are the strongest in their food chain. But in fact, around 70 million sharks are caught and traded in this industry every year. The numbers of some kinds of sharks have fallen by over 90 percent in the last 20 to 30 years. ④
Environmental protection groups around the world, such as Wild Aid and the WWF, are teaching the public about “finning”. They have even asked governments to develop laws to stop the sale of shark fins. ⑤ So far, no scientific studies have shown that shark fins are good for health, so why eat them ⑥ Help save the sharks！
Number of sharks caught and traded every year
How governments can help
Two environmental groups against “finning” ⑦
around 70 million
develop laws to stop the sale of shark fins
Wild Aid and the WWF
3b Read the passage again and fill in the blanks with the words in the box.
so　　although　　if but　　when
1. Many people do not realize they are killing a whole shark ________ they enjoy a bowl of shark fin soup.
2. Sharks are at the top of the food chain, ________ if their numbers drop, the ocean’s ecosystem will be in danger.
when
so
3. Many think that sharks are too strong to be endangered, _______ they are wrong.
4. __________ there are no scientific studies to support this, a lot of people believe that shark fins are good for health.
5. Sharks may disappear one day ________ we do not do something to stop the sale of shark fins.
Although　
if
but
so　　although　　if but　　when
①This is not only cruel, but also harmful to the environment.
(1) not only... but also... 不但……而且……
not only... but also... 是并列连词词组, 可以连接并列的成分。其中also可以省略。
Not only I but also my sister likes going shopping online.
不仅我, 而且我妹妹也喜欢网购。
连接并列主语
当not only... but also...连接两个主语时，谓语动词的单复数形式遵循“就近原则”，即要和最近的名词或代词的单复数保持一致。
连接并列表语
Astronauts can not only give classes but also write in the spaceship.
宇航员们在宇宙飞船里不但能够授课还能写字。
The government provides these homeless people with not only food but also clothes.
政府给这些无家可归的人不仅提供食物，而且提供衣服。
连接并列谓语
连接并列宾语
拓展：(1) 当not only... but also... 连接两个句子，且not only放在句首表示强调时，其后的句子要用部分倒装，而but also后的句子仍用陈述语序。
Not only is he a teacher, but he is also a poet.
他不仅是一位教师，而且也是一位诗人。
(2) 连接并列成分的结构还有：both... and...(……和……都) ；either...or...(要么……要么……) ；neither... nor...(……和……都不) 。
小贴士：在英语中，为了强调某些内容，常把否定词置于句首，这时句子用倒装语序。常见的这类词还有never，little，hardly等。
考题1: ______ Jake ______ his mother likes pop songs, and they often sing together.
A. Not only; but also
B. Neither; nor
C. Either; or
A
(2) cruel /'kru l/ adj. 残酷的；残忍的
I think it’s cruel to keep animals in cages.
我认为把动物们关在笼子里是残忍的。
I can’t stand people who are cruel to animals.
我无法容忍虐待动物的人。
be cruel to 意为“对……残忍”
cruel的副词形式为cruelly，意为“残忍地”。
考题2: No matter how c the reality may be, we should never give up.
ruel
(3) harmful /'hɑ (r) mfl/ adj. 有害的
是由“harm(n. 伤害；损害) +-ful(形容词后缀) ”构成的。be harmful to 意为“对……有害”。
Smoking is harmful to one’s health.
吸烟对人的健康有害。
harmful 的比较级、最高级分别借助more、 most构成。
拓展：be harmful to 的同义短语为do harm to 或be bad for。反义短语为be good for “对……有好处”。
Fruit juice can be harmful to children’s teeth. = Fruit juice can do harm to children’s teeth. = Fruit juice can be bad for children’s teeth. 水果汁会对儿童的牙齿有害。
Cycling is a good way of getting around in this city. It’s good for the environment.
在这个城市，骑自行车是出行的好方式。这对环境有好处。
构词法记单词：-ful 是形容词后缀，加在名词后构成形容词，表示“充满……的”或“具有……性质的”。如：
helpful 有帮助的
useful 有用的
wonderful 精彩的
meaningful 有意义的
careful 细心的；小心的
colorful 颜色鲜艳的
知识积累：
be good with...
善于应付……的
be thirsty for...渴望……
be different from...
与……不同
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考题3: Too much sugar can ______ your health. So eat less sugar.
A. be good with B. be harmful to
C. be thirsty for D. be different from
B
②Without a fin, a shark can no longer swim and slowly dies.
no longer 不再
The weather was so hot that I could stand it no longer.
天气太热了，以至于我再也无法忍受。
Jack no longer felt lonely after making some friends in the new school.
杰克在新学校交了一些朋友后就不再感到孤独了。
no longer 相当于not... Any longer，一般和延续性动词连用。强调时间或动作不再持续。
考题4: [无锡] Jim is no _________ (long) afraid of making new friends at school now.
longer
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③Sharks are at the top of the food chain in the ocean’s ecosystem.
at the top of 在……顶部或顶端
反义短语为at the bottom of“在……的底部”。
She was standing at the top of the stairs.
她站在楼梯的顶端。
拓展：on the top of 意为“在……之上；在……上面”。on 表示部位上的接触，反义短语为at the foot of“在……脚下”。
Place the bowl on the top of the fridge.
把这个碗放到冰箱的上面。
一语辨异: Life is always about ups and downs. You won’t always be at the top, but you won’t always be at the bottom either. 人生总是充满了起起落落。你不会一直站在顶峰，也不会一直处于低谷。
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④The numbers of some kinds of sharks have fallen by over 90 percent in the last 20 to 30 years.
(1) (重点) the number of... ……的数量
The numbers of different kinds of plants have already fallen year by year. 不同种类的植物的数量已经在逐年下降。
the numbers of 是the number of 的复数形式，此处number使用复数，表示不同种类的鲨鱼的数量。
辨析: the number of 与a number of
the number of 意为“……的数量”，后接复数名词或复数代词，其中心词是number。“the number of + 复数名词或代词的复数形式”作主语时，谓语动词用单数形式。
a number of 意为“一些；许多”，后接复数名词或复数代词，可在number 前使用large、small 等词来修饰，其中心词是of 后面的名词或代词。a number of 后加名词作主语时，谓语动词用复数形式。
一语辨异：
A number of steps have been taken to protect wild animals because the number of them has become smaller and smaller.
为了保护野生动物，已经采取了一些措施，因为它们的数量变得越来越少。
The number of these colorful butterflies has dropped in recent years. 近年来，这些彩色蝴蝶的数量有所下降。
A number of books have been written on the subject of artificial intelligence.
已经有许多关于人工智能主题的书籍被撰写出来。
考题5: In China, a number of birthday persons _____ cakes with candles. The number of candles _____ the person’s age.
A. has; is B. eats; are C．eat; is
【点拨】主谓一致法解题。a number of + 复数名词作主语时，谓语动词也用复数，所以第一空用eat；The number of + 名词作主语时，谓语动词用单数，所以第二空用is。
C
(2) fall by 下降了……
其中by 用作介词，表示下降的幅度。
Output will fall by 6%. 产量将下降6%。
拓展：fall to 意为“下降到”。
(3) percent /p 'sent/ n. 百分之……
percent 作名词，意为“百分之……”，用在基数词之后。
Thirty percent of the farmland has been bought.
百分之三十的农田已经被买下了。
一语辨异:
Last year, the price of this kind of car was 100,000 yuan. This year it falls to 80,000 yuan. It falls by 20 percent.
去年这种小汽车的价格是10万元，今年降到了8 万元，下降了百分之二十。
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拓展：当“基数词 + percent of + 名词”结构作主语时，谓语动词要与of 后面的名词保持单复数一致。
Sixty percent of the students are boys in this class.
这个班 60% 的学生是男生。
Fifty percent of my task has been done.
我的任务已经完成百分之五十。
无论基数词是否大于1，percent 都用单数形式。
⑤They have even asked governments to develop laws to stop the sale of shark fins.
law /l / n. 法律；法规
Do not think you are above the law.
别以为你凌驾于法律之上。
I think our government should pass a law to reduce food waste.
我认为我们的政府应该通过一项法律来减少食物浪费。
He is a lawyer. He always tells us to obey the law and those who break the law will be punished by law. 他是一个律师。
他总是告诉我们要遵守法律，那些违法者将受到法律制裁。
lawyer 作名词，意为“律师”。
law 的常用短语：develop laws 制定法律
pass a law 通过一项法律 break the law 违法
obey the law 遵守法律 traffic laws 交通法规
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考题6: Our government made some ________ (法律) to care about the left-behind kids.
laws
⑥So far, no scientific studies have shown that shark fins are good for health, so why eat them
(1) so far 到目前为止
Mary started reading the book last week and she has finished
50 pages so far.
玛丽上周开始读这本书，到目前为止她已经读完了50 页。
How many travelers have been to Disneyland so far
到目前为止有多少游客到过迪斯尼乐园？
拓展：so far 还可意为“(距离) 如此远”。
I’m not sure to walk so far. 我没有把握能步行那么远。
so far 通常与现在完成时连用，用作状语，可位于句首或句末。同义词组有up to now(到现在为止) 。
考题7: As a traditional Chinese martial art (武术) , Taijiquan ______ to more than 150 countries all over the world so far.
A. spreads B. is spreading
C. will spread D. has spread
【点拨】考查动词时态。根据“so far”可知，时态是现在完成时，结构是“have/has done”。
D
(2) scientific /sa n't f k/ adj. 科学上的；科学的
It’s not a scientific way to test their opinions.
它不是检验他们观点的一个科学的方式。
拓展：scientific 的词形变化：
science n. 科学
scientist n. 科学家
一语辨异:
I am interested in science and want to be a scientist, so I take part in many scientific activities. 我对科学感兴趣，想成为一名科学家，所以我参加了许多科学活动。
考题8: China plans to pay more attention to __________________ (科学教育) in its primary and middle schools.
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scientific education
⑦Two environmental groups against “finning”
against / 'ɡenst/, / 'ɡe nst/ prep. 反对
against 作介词，其反义词为for。后接名词、代词或动名词。
I’m not against your ideas. Instead, I’m for you.
我不反对你的观点。相反，我支持你。
I am against smoking in public places.
我反对在公共场合抽烟。
拓展：against 的其他常见含义：
We will play against the league champions next week.
下周我们要和联赛冠军队比赛。
Put the piano there, against the wall.
把钢琴放在那儿，紧靠着墙。
Lin Yi rode his bike ahead against the strong wind.
林义逆着大风向前骑车。
He walked without looking ahead and hit his head against the tree. 他走路不看前方，头撞到树上了。
考题9: We need to guard _____ any possible danger around us.
A. for B. over
C. with D. against
【点拨】用固定搭配法。guard against 为固定搭配，意为“提防；防范”。
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D
本节课主要学习了呼吁拯救鲨鱼的文章, 掌握了知识点not only…but also…, harmful, the number of, against的用法, 增强了拯救濒危动物、爱护人类生存环境的意识。