北师大版(2019)选择性必修第一册Unit 3 Conservation Lesson 1 The Sixth Extinction 课件 (共24张PPT)

(共24张PPT)
Lesson 1 The Sixth Extinction
Unit3 Conservation
Reading
01
Before we read
The Five Major Mass Extinctions
01
02
03
04
二叠纪(the Permian period)
95% die out
82% die out
76% die out
80% ddie out out
三叠纪(the Triassic period)
白垩纪(the Cretaceous period)
小行星或彗星坠落地球
05
泥盆纪(the Devonian period)
85% die out
奥陶纪（the Ordovician period)
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
1
How many times up to today has life on Earth almost died out
a. Once
b. Five times
c. More than 10 times
How much do you know about extinction
So will there be
a six extinction
02
While-reading
Make a match
Background information
Causes
Consequences
Solutions
Para4
Para1
Para2
Para3
单击此处输入标题文本
Para1
Para2
Background information
Causes
Consequences
Solutions
Para3
Para4
Read the text and complete the notes.
Definition of extinction
The entire species are wiped out
Number of times
Over 90% of all species that
ever lived
Two notable extinctions
The third mass extinction, killed 90% to 96% of all species;
The fifth event caused the death of the dinosaurs
Main reasons for extinctions
1.volcanic eruptions,
2.asteroids hitting the Earth from space,
3. changes in sea levels, the decrease of oxygen content of the sea,global warming
How to avoid the sixth mass extinction
1. Change the way we live, including setting up special areas where plants and animals can be protected;
2. Change how we work and travel by using cleaner, more natural sources of energy; improve our farming methods
03
Intensive reading
Read again and 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
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
The case study showed that even in desperate situations, we can do something to help. In short, it’s never too late.
Which claim (s) did the case study support in the text
04
Summary
Causes
D
Overfishing
C
Factory farming
B
Forests being destoryed
A
Air and wate pollution
Consequneces
C
human beings die out
B
Nature balance broken
A
3/4 species die out
Solutions
C
Take steps to save endangered species
B
Change the way we live
A
Improve farming methods
Brainstorm(Group of 4)
What are other ways can we figure out to avoid exrtinction
Watch a video and think about the importance of protecting the earth today!
05
Homework
Name one or two phenomenon that you think is assosiated with the extinction of species and figure out possible solutions thus writing down your proposals within 100 words.
THANK YOU