北师大版（2019）选择性必修 第一册Unit 3 Conservation Lesson 1 The Sixth Extinction课件 (共36张PPT)

(共36张PPT)
Lesson 1　The Sixth Extinction
CONSERVATION
UNIT 3
1.To read and talk about conservation;
2.To read for general understanding;
3.To read for specific information and understanding words in the context;
4.To express solutions to environmental problems.
Pre-reading
1. What does the word “Extinction” mean
Extinction is a situation in which something no longer exists on our planet.
1. How many times up to today has life on Earth almost died out
A. Once. B. Five times. C. More than 10 times.
2.About what percent of all species on Earth became extinct during the mass extinction known as the “Great Dying”
Less than 10%. B. Nearly 50%. C. More than 90%.
3. What do scientist think will cause the next mass extinction
A. Human activity. B. Natural causes. C. Unknown reasons.
2. How much do you know about extinction Choose the option based on your knowledge.
Read the passage quickly and match the main idea with each paragraph.
Para.1 A. Human activity causes species to die out faster.
Para.2 B. How do we avoid a sixth mass extinction
Para.3 C. Extinctions in history and the reasons.
Para.4 D. The possible consequences of the sixth mass extinction.
While-reading
___________ are not unusual in our Earth’s history. But we humans can _________ to stop destroying the planet we live on to avoid___________________.
2. What is the main idea of the passage
Extinctions
take action
a sixth extinction
3. What is the type of this article
A. Narration (记叙文).
B. Argumentative Essay (议论文).
C. Expository Writing (说明文).
D. News Report (新闻报道).
√
1. How many times up to today has life on Earth almost died out
A. Once. B. Five times. C. More than 10 times.
2.About what percent of all species on Earth became extinct during the mass extinction known as the “Great Dying”
Less than 10%. B. Nearly 50%. C. More than 90%.
3. What do scientist think will cause the next mass extinction
A. Human activity. B. Natural causes. C. Unknown reasons.
How much do you know about extinction Choose the option based on your knowledge.
4. Check your answers to the activity in Pre-reading.
√
√
√
(3) Two notable extinctions and their consequences __________________________________________
(2) The number of extinctions that have occurred so far __________
(4) Main reasons that cause extinctions___________________________________
(1) Meaning of extinction
__________________________________________
1.Read the first paragraph and complete the notes.
Para. 1
(1) Meaning of extinction
Extinctions are________ entire species are wiped out, ______ are not unusual in our Earth’s history.
where
which
(2) The number of extinctions that have occurred so far
In the past 500 million years, there have been__________ extinctions, in which ___________________ that ever lived are now extinct.
five times
over 90% of all species
(3) Two notable extinctions and their consequences:
The _______ mass extinction, known as the “Great Dying”, which killed _____________of all species.
The ______ event, which occurred 66 million years ago, caused the death of the ___________.
third
90% to 96%
fifth
dinosaurs
(4) Main reasons that cause extinctions
________________.
Asteroids hitting the Earth from space
Changes in sea levels.
The decrease of the oxygen content of the sea.
________________.
Global warming
Volcanic eruptions
2. Which writing method is NOT used in this paragraph
A.Giving data.
B.Analyzing cause and effect.
C.Making comparison.
D.Arranging in the time order.
√
3. Paraphrase the following sentence.
Many scientists say we are now entering the Earth’s sixth mass extinction. This time, human activity will be to blame.
Many scientists hold the idea that we are about to go through the sixth extinction which human activity should be responsible for.
1. What did scientists find out in 2015
They found that human activity is causing species to die out 1,000 times faster than normal.
2. What are the reasons why so many species are dying out
Para. 2
The reasons are varied, such as air and water pollution, forests being destroyed, factory farming and overfishing.
3. Which sentence in this paragraph can replace the following one
What is obvious is that our human activity has had a negative influence on all other species on Earth, such as animals and plants.
It is clear that human activity has negatively affected all other species on Earth, including animals and plants.
1. What would happen if a sixth mass extinction occurs
▲Up to _____________of all species on Earth could die out.
▲Humans would also be _________ dying out, because our world and lives depend on ___________ in nature.
three quarters
at risk of
the balance
Para. 3
3. Paraphrase the following sentence.
Without forests, we would have no air to breathe, and without clean water we would be unable to survive.
If there were no forests, we would not breathe；if there were no clean water, we would die.
1. What is the purpose of the last paragraph
A.Call on people to protect the Earth.
B.Blame people for destroying the environment.
C.Urge the government to take action.
D.Warn the public to reduce their destructive behaviour.
Para. 4
√
2. What should we do to protect the earth
▲take steps to save (1)___________________ ;
▲change the way (2)__________________ by using cleaner, more natural sources of energy
▲improve farming methods to (3) _________ water, air and land pollution
endangered species
we work and travel
reduce
3.What rhetorical devices(修辞手法) does the author use in this paragraph
A.Metaphor(暗喻)．
B.Personification(拟人)．
C.Overstatement(夸张)．
D.Parallel construction(排比)．
√
Case Study
Read the Case Study and do the following exercises.
1. What did people do to protect black robins
▲Wildlife workers began (1)____________ for raising black robin chicks.
▲They (2)_________ Old Blue’s eggs, helped them to (3)______ and took care of their (4)________.
▲They (5)_________ their habitats and (6)__________ small animals that hunt them from the islands where they live.
a programme
protected
hatch
chicks
restored
removed
2. What is the effect of their efforts
In 1980
Now
There were only 5 black robins left in the world, only one of which was able to lay eggs.
There are more than 250 black robins and the population is still spreading.
3.Which claim did the Case Study support in the text
A.Humans can do whatever they want.
B.The black robins are successfully saved from extinction.
C.It is human activity that has affected the species negatively.
D.It’s never too late to take action to protect the environment.
√
1.Use different coloured pens to highlight at least one example for each of the following elements listed below. Then find out what typical language is used (Critical thinking）
Facts:
Reasons:
Opinions/predictions:
Solutions:
Post-reading
Suggested answer：
Facts: over 90 percent of all species that ever lived are now extinct; ...the third mass extinction, known as the “Great Dying”, which killed 90% to 96% of all species. And the fifth event... caused the death of the dinosaurs; human activity is causing species to die out 1,000 times faster than normal.
Reasons: air and water pollution, forests being destroyed, factory farming and overfishing are causing species to die out; Without forests, we would have no air to breathe, and without clean water we would be unable to survive.
Opinions/ predictions: Many scientists say we are now entering the Earth ’s sixth mass extinction; scientists believe that up to three quarters of all species on Earth could die out.
Solutions: We need to take steps to save endangered species; we need to change how we work and travel...; we also need to improve our farming methods to reduce water, air and land pollution; In short...we need to stop destroying the planet that we live on and start to protect it.
2.What should we do as students to avoid the sixth extinction and protect the environment (Creative thinking)
Suggested answer:
Firstly, we should raise awareness of environmental protection, knowing that whatever we do will have some effects on the environment. Secondly, we should pay attention to our daily behavior and try our best to save environment and reduce the harm to it, for example, we can stop using plastic bags, save water and electricity and learn to recycle and reduce in daily life.
Conservation is a state of harmony between men and nature. —Walter Chrysler
Environmental pollution is an incurable disease. It can only be prevented. —Barry Commoner
Reflection
Take with restraint and use in moderation; this way one shall always know contentment. (Zizhi Tongjian)
取之有道，用之有节，则长足。
Extinctions, where entire species are wiped out, are not unusual in our Earth’s history. In fact, over 90 percent of all species 1.____ ever lived are now extinct. In the last 500 million years，there 2.________(be) five times when life on Earth has almost ended, 3._________(include) the third mass extinction, known as the “Great Dying”．The reasons for extinctions are 4.____________(vary)．Many scientists say we are now entering the Earth’s sixth mass extinction. This time, human activity will be 5.________(blame)．
that
have been
including
varied/various
to blame
A 2015 study by scientists found that human activity is causing species to die out 1,000 times 6._____(fast) than normal. 7.______ is clear is that human activity has negatively affected all other species on Earth, including animals and plants.
If a sixth mass extinction 8.______(occur), scientists who have studied the issue believe that up to three quarters of all species on Earth could die out and we would also be 9.___ risk of dying out. In short, if we want to survive, we need to stop 10.____________(destroy) the planet that we live on and start to protect it.
faster
What
occurs
at
destroying
Para.1
Extinctions, where entire species are wiped out, are not unusual in our Earth’s history. In fact, over 90 percent of all species that ever lived are now extinct. In the last 500 million years, there have been five times when life on Earth has almost ended. These include the third mass extinction, known as the “Great Dying”，which killed 90% to 96% of all species. And the fifth event, which occurred 66 million years ago, caused the death of the dinosaurs. The reasons for extinctions are varied. According to scientists, they include volcanic eruptions, asteroids hitting the Earth from space, changes in sea levels, the decrease of the oxygen content of the sea and global warming. Many scientists say we are now entering the Earth’s sixth mass extinction. This time, human activity will be to blame.
“彻底毁灭”
引导定语从句，先行词是extinction
that引导的定语从句，先行词是species
when引导的定语从句，先行词是times
过去分词短语作后置定语
引导非限制性定语从句
引导定语从句，先行词是the fifth event
“各种各样的，形形色色的”
省略that的宾语从句，作say的宾语
“把……归咎于”
Analyze the key points of the text
Para.2
Although it is not unusual for species to die out naturally, the rate
at which this is now happening is cause for concern. A 2015 study by scientists who were based at Brown University and Duke University in the US, looked at how quickly species die out due to natural causes, that is, the “background extinction rate”. They found that human activity is causing species to die out 1,000 times faster than normal. There is a long list of reasons why so many species are dying out: air and water pollution, forests being destroyed, factory farming and overfishing. It is clear that human activity has negatively affected all other species on Earth, including animals and plants.
although引导让步状语从句
“介词＋which”引导的定语从句，其先行词是rate
引导定语从句，先行词是scientists
作插入语，“也就是说”
引导宾语从句，作found的宾语
引导定语从句，先行词是reasons
It is adj.+that...句式，其中it作形式主语，that引导主语从句
“灭绝”
Para.3
If a sixth mass extinction occurs, scientists who have studied the issue believe that up to three quarters of all species on Earth could die out. Of course, as we humans depend on so many species for our survival, we would also be at risk of dying out. Our world and our lives depend on the balance in nature between animals and plants. Without forests, we would have no air to breathe, and without clean water we would be unable to survive.
引导条件状语从句
who引导定语从句，先行词是scientists
that引导宾语从句, 作believe的宾语
引导原因状语从句，意思是“因为，由于”
“处境危险，受到威胁”
Without “（如果）没有……”, 后跟虚拟条件句
Para.4
Can a sixth extinction be avoided Experts say that it is not yet too late, if we take action now.This would mean we have to significantly change the way we live. For example, we need to take steps to save endangered species, including setting up special areas where plants and animals can be protected. We need to change how we work and travel by using cleaner, more natural sources of energy, such as wind and solar energy. We also need to improve our farming methods to reduce water, air and land pollution. In short, if we want to survive, we need to stop destroying the planet that we live on and start to protect it.
引导宾语从句
引导条件状语从句
省略that的宾语从句，作mean的宾语
省略that或in which的定语从句，先行词是the way
“濒危物种”
引导定语从句，在从句中作状语
how引导的宾语从句，作change的宾语
“简而言之”
引导条件状语从句
引导定语从句，在从句中作live on的宾语
Case Study
The black Robin
Black robins are the birds that humans saved from extinction, In 1980, there were only five black robins left in the world. They all lived on a small island off the coast of New Zealand. Only one of those birds, a female called Old Blue, was able to lay eggs. Wildlife workers began a programme for raising black robin chicks. They protected Old Blue’s eggs, helped them to hatch and took care of their chicks. Thanks to their efforts, there are now more than 250 black robins, and the population is spreading. To help them survive, people are restoring their habitats and removing small animals that hunt them, such as mice and cats from the islands where they live.
引导定语从句，在从句中作save的宾语
过去分词短语作后置定语， 修饰black robins
同位语, called...是过去分词短语作后置定语
“产卵，下蛋”
protected，helped，took care of三个谓语动词并列
不定式作目的状语
引导定语从句，在从句中作主语，先行词是animals
where引导的定语从句，先行词是the island
Homework
Preview language points and recite the key points of the text.