北师大版（2019）选择性必修 第一册Unit 3 Conservation Lesson 1The Sixth Extinction Period 1 课件(共31张PPT)

(共31张PPT)
Unit 3 Conservation
Lesson 1 The Sixth Extinction(1)
At the end of the lesson, students will be able to:
1.能获取文章的主要信息、观点，理解语篇的意义，了解物种灭绝的史实和原因及应采取的行动；
2.能区分语篇中的主要事实和观点，识别语篇的文体类型、写作手法和逻辑结构；
学习理解
应用实践
迁移创新
3.能结合文章逻辑结构描述物种灭绝的史实、原因及应采取的行动；
4. 通过对物种灭绝问题的分析和讨论，运用“事实—原因—解决”的逻辑表达方式谈论某种濒危动物。
Learning objectives
What is extinction
Extinction: a situation in which something no longer exists on our planet.
Activate and share
Activity 1 How much do you know about extinction Choose the option based on your knowledge.
1. How many times up to today has life on Earth 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”
a. Less than 10%. b. Nearly 50%. c. More than 90%.
3. What do scientists think will cause the next mass extinction
a. Human activity. b. Natural causes. c. Unknown reasons.
Activity 2 Read the text quickly and check your answers in Activity 1.
1. How many times up to today has life on Earth 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”
a. Less than 10%. b. Nearly 50%. c. More than 90%.
3. What do scientists think will cause the next mass extinction
a. Human activity. b. Natural causes. c. Unknown reasons.
Read and Explore
Read the text quickly and match the headings to each paragraph.
Para.1
Para.2
Para.3
Para.4
how we can do
who to blame(causes/reasons)
what might happen
background history
Activity 3 Read the text again. Complete the notes. Then talk about the different aspects of extinctions.
entire species are wiped out
five
the 3rd mass extinction, killed 90% to 96% of all species; the 5th event, caused the death of dinosaurs
Main reasons that cause extinctions:
volcanic eruptions, asteroids hitting the Earth from space, changes in sea levels, the decrease of the oxygen content (含氧量) of the sea and global warming
How to avoid the sixth mass extinction:
change the way we living, including setting up special areas where plants and animals can be protected; change how we work and travel by using cleaner, more natural sources of energy, such as wind and solar energy; improve our farming methods
Talk about the different aspects of extinctions according to the mind map.
Activity 4 Read again. Answer the questions.
1. What did scientists find out in 2015
2. Why does the writer think the sixth mass extinction will come
3. Why does the writer believe we’ll probably die out if 75% of the Earth’s species die out
4. What did people do in the case study to protect black robins Which claim(s) did the case study support in the text
1. What did scientists find out in 2015
The 2015 study looked at how quickly species die out due to natural causes, that is, the “background extinction rate”. The scientists found that human activity is causing species to die out 1,000 times faster than normal.
2. Why does the writer think the sixth mass extinction will come
Because human activity has negatively affected all other species on Earth, including animals and plants.
3. Why does the writer believe we’ll probably die out if 75% of the Earth’s species die out
Because our world and our lives depend on the balance in nature between animals and plants.
4. What did people do in the case study to protect black robins Which claim(s) did the case study support in the text
People protected Old Blue’s eggs, helped them to hatch, and took care of the chicks. People are restoring their habitats, and removing pests like mice and cats from the islands where they live. The case study showed even in desperate situations, we can do something to help. In short, it’s never too late.
Activity 5 Use different coloured pens to highlight at least one example for each of the four elements listed below in different colours and then answer the following questions.
Facts:
Over 90 percent of all species that ever lived are now extinct.(P1)
In the last 500 million years, there have been five times when life on Earth has almost ended.(P1)
Human activity is causing species to die out 1,000 times faster than normal.(P2)
…
Opinions/Predictions:
Many scientists say we are now entering the Earth’s sixth mass extinction.(P1)
Scientists believe that up to three quarters of all species on Earth could die out.(P3)
…
Reasons:
The reasons for extinctions are varied. 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.(P1)
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.(P2)
…
Solutions:
We need to take steps to save endangered species, including setting up special areas where plants and animals can be protected.(P4)
We need to change how we work and travel by using cleaner, more natural sources of energy.(P4)
We also need to improve our farming methods to reduce water, air and land pollution.(P4)
…
Answer the following questions.
What text type is this piece of writing
What is its communicative purpose
What typical language is used
4. What ways of argument does the writer use to convince readers Are you convinced Why or why not
This piece of writing is an exposition.
What text type is this piece of writing
Narration (记叙文)
Description (描写文)
Exposition (说明文)
Argumentation (议论文)
Its purpose is to explain what the sixth extinction is and its effects and call on people to take action to prevent it from happening.
2. What is its communicative purpose
The language in the article is formal and impersonal, objective and accurate, and concise and clear. The writer avoids using colloquialisms(口语), the first person, and expressions like “I believe” “I think” “probably” “perhaps” or “maybe”. The words and sentences are simple, plain and easy to understand.
3. What typical language is used
The writer uses ways such as citing ideas from experts or authorities, giving examples and using data. I believe that if we take action now it is not too late to save other species from extinction. The black robin was saved from extinction when only five birds remained, so I think it is possible to save any species if we act right now.
4. What ways of argument does the writer use to convince readers Are you convinced Why or why not
Activity 6 Use the adjectives and nouns to make meaningful expressions.
Focus on Language
1. Act now before ___________ are lost to global warming.
2.Natural reserves should be set up to provide home for _________________.
3.The pandemic has brought about a _______________ in the way we work.
4.China is rich in ______________.
5.Evidence shows that human activity is to blame for the current _____________.
6.Costs for __________ have been declining, as technology improves.
entire species
endangered animals
significant change
natural resources
mass extinction
solar energy
Complete the sentences with the correct forms of the expressions in Activity 6.
Option 1
气候变化是所有物种面临的最紧迫的威胁。（entire species）
Climate change is the most urgent threat facing our entire species.
2. 照料濒危动物是我们的职责。（endangered animals）
It is our duty to care for endangered animals.
3. 他忽视了税务法律中的一个重大变化。（significant change）
He neglected a significant change in the tax laws.
4. 政府应该采取一些措施去保护自然资源。（natural resources）
The government should take some measures to preserve the natural resources.
Translate the sentences into English with the help of the expressions in Activity 6.
Option 2
5. 这是个关于在大规模的物种灭绝时代如何保护野生动物的故事。（mass extinction）
This is a story of wildlife conservation in the age of mass extinction.
6. 太阳能是一种新型能源。（solar energy）
Solar energy is a new kind/type/sort of source of energy.
Translate the sentences into English with the help of the expressions in Activity 6.
Option 2
Activity 7 Complete the paragraph about extinction using the correct form of the phrases below.
In the last 500 million years, there have been five mass extinction events on Earth. In the third event, which __________ the “Great Dying”, 90% to 96% of all species _______. Of course, species died out due to many causes. But nowadays, human activity __________ all types of species that we _________ for living. We need to _________ to avoid the sixth mass extinction. We should _________ to save endangered animals and plants, and ______ special areas to __________ them before the next extinction comes that may ________ the entire species.
is known as
died out
has affected
depend on
take action
take steps
set up
take care of
wipe out
Suppose your school will hold a speech contest to get more students to care about extinction. Try to make a speech about an endangered species you know and call on students to protect endangered animals.
You may organize your speech from the following aspects:
The history of extinction
The reasons for its extinction
The actions people can take to avoid its extinction
…
Express Yourself
Polish your speech and write it down on your worksheet.
Homework