1、,选择性必修一 Unit 3 Conservation(1),The Sixth ExtinctionReading(1),Activate and share,extinction,Activate and share,1.What is extinction?,Extinction is a situation in which something no longer exists.,dinosaur,Activate and share,2.How much do you know about extinction?,How many times up to today has life
2、 on Earth almost died out?A.Once.B.Five times.C.More than 10 times.,Activate and share,About which 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%.,Activate and share,What do scientists think will cause
3、the next mass extinction?A.Human activity.B.Natural causes.C.Unknown reasons.,Read and explore,1.Read the passage and finish the two tasks:Check whether your answers in the quiz are right.Get the main idea of each paragraph.,Read and explore,Check the answers in the quiz.,How many times up to today
4、has life on Earth almost died out?A.Once.B.Five times.C.More than 10 times.,Read and explore,About which 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%.What do scientists think will cause the next mass
5、extinction?A.Human activity.B.Natural causes.C.Unknown reasons.,Read and explore,Get the main idea of each paragraph.,Para.1:Para.2:Para.3:Para.4:,Background history of the sixth extinction,Causes of the sixth extinction,Effects of the sixth extinction,What we can do to prevent the sixth extinction,
6、Read and explore,Background history,Causes,Effects,Solutions,TheSixthExtinction,Development of the passage,Read and explore,2.Read the passage again and complete the notes.,Extinction,Read and explore,Extinction,entire species are wiped out,Read and explore,Extinction,over 90%of all species that eve
7、r lived,Read and explore,Extinction,the third mass extinction killed 90%to 96%of all species;the fifth event,which occurred 66 million years ago,caused the death of dinosaurs.,Read and explore,Extinction,volcanic eruptions,asteroids hitting the Earth from space,changes in sea levels,the decrease of
8、oxygen content of the sea,global warming,Read and explore,Extinction,change the way we live,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;improve our farming methods,Read and explore,Retell t
9、his part of the passage according to your notes.,Extinction,Read and explore,Retelling,Extinction means the entire species are wiped out.So far over 90%of all species that ever lived are extinct.Along the history,there are 2 notable extinctions,the third one and the fifth one.During the third mass e
10、xtinction,known as the“Great Dying”,90%to 96%of all species died out.The fifth one,which occurred 66 million years ago,caused the death of dinosaurs.,Read and explore,Retelling,There are many reasons that cause extinctions,such as volcanic eruptions,asteroids hitting the Earth from space,changes in
11、sea levels,the decrease of oxygen content of the sea and global warming.,Read and explore,Retelling,The good news is that we can do something to avoid the sixth mass extinction.Firstly,we have to significantly change the way we live.We need to take steps to save endangered species,including setting
12、up special areas where plants and animals can be protected.Also,we can change how we work and travel by using cleaner and more natural sources of energy,such as wind and solar energy.We also need to improve our farming methods.,Read and explore,3.Read the passage again and answer the questions.,What
13、 did scientists find out in 2015?Why does the writer think the sixth mass extinction will come?Why does the writer believe well probably die out if 75%of the Earths species die out?What did people do in the case study to protect black robins?Which claim(s)did the study support in the text?,Read and
14、explore,What did scientists find out in 2015?The study 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.,Read and explore,Why does the writer think the sixth
15、 mass extinction will come?Because human activity has negatively affected all other species on Earth,including animals and plants.,Read and explore,Why does the writer believe well probably die out if 75%of the Earths species die out?Because our world and our lives depend on the balance in nature be
16、tween animals and plants.,Read and explore,What did people do in the case study to protect black robins?Which claim(s)did the study support in the text?People protected Old Blues eggs,helped them to hatch,and took care of the chicks.People are restoring their habitats and removing pests like mice an
17、d cats from the islands where they live.What we can do to prevent the sixth extinction,Read and explore,Causes,Effects,An example of protection,TheSixthExtinction,Retell this part of the passage.,Read and explore,The study in 2015 found that human activity is causing species to die out 1,000 times f
18、aster than normal.It is clear that human activity has negatively affected all other species on Earth,including animals and plants.,Retelling,Read and explore,Retelling,There is no doubt that our world and our lives depend on the balance in nature between animals and plants.If 75%of the Earths specie
19、s disappear,we human beings will also face the risk of dying out.,Read and explore,Retelling,The good news is that people are doing something to protect animals and plants on Earth.For example,people are taking measures to protect an endangered bird called Old Blue.Through our efforts,the number of
20、this bird is increasing steadily.Therefore,you see,we can do something to help the earth and its never too late to act.,Think and share,As a student,what do you think you can do to help the Earth?,reduce waste,put rubbish into separate dustbins,cycle or take public transportation,use fewer plastic bags while going shopping,Summary,Background history,Causes,Effects,Solutions,TheSixthExtinction,Homework,1.Read the passage aloud.2.Write a short passage about the sixth extinction.,Thank you!,
