Unit 3 Lesson 1 The Sixth Extinction（ppt课件）-2022新北师大版（2019）《高中英语》选择性必修第一册.pptx

1、Unit 3 ConservationLesson 1 The Sixth Extinction()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?Choose the option based on your knowledge.()2.About what percent of all species on Earth became extinct duri

2、ng 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.Predicting()1.How many times up to today has life on Earth almost died out?a.Once.b.Five

3、times.c.More than 10 times.How much do you know about extinction?Choose the option based on your knowledge.()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

4、 cause the next mass extinction?a.Human activity.b.Natural causes.c.Unknown reasons.bcaRead and checkMeaning of extinctionHow to avoid the sixth mass extinctionMain reasons that cause extinctionsTwo notable extinctions and their consequencesThe number of extinctions that have occurred so farExtincti

5、onRead the text.Complete the notes.Then talk about the different aspects of extinctions.结果结果Read for details1.Meaning of extinction:entire species are wiped outRead the text.Complete the notes.Then talk about the different aspects of extinctions.Extinctions,where entire species are wiped out,are not

6、 unusual in our Earths history.Para 1 彻底毁灭彻底毁灭Read for language points2.The number of extinctions that have occurred so far:over 90%of all species that ever livedPara 1 In fact,over 90 percent of all species that ever lived are now extinct.灭绝的灭绝的3.Two notable extinctions and their consequences:Para

7、1 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 third ma

8、ss extinction,which killed 90%to 96%of all species;the fifth event,which occurred 66 million years ago,caused the death of the dinosaurs恐龙恐龙包括包括4.Main reasons that cause extinctions:volcanic eruptions,asteroids hitting the Earth from space,changes in sea levels,the decrease of oxygen content of the

9、sea,global warmingPara 1 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.原因原因多样的多样的5.How to avoid the sixth mass extinction:Can

10、 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 ne

11、ed 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 prote

12、ct it.Para 4 change the way we live,e.g.save endangered species,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 methodsRead again.Answer the questions.1.What did scientists

13、find out in 2015?2.Why does the writer think the sixth mass extinction will come?3.Why does the writer believe well probably die out if 75%of the Earths 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?Read for detail

14、s1.What did scientists find out in 2015?The study found 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.Para.22.Why does the writer think the sixth mass extinction wi

15、ll come?Because human activity has negatively affected all other species on Earth,including animals and plants.Para.2It is clear that human activity has negatively affected all other species on Earth,including animals and plants.3.Why does the writer believe well probably die out if 75%of the Earths

16、 species die out?Because our world and our lives depend on the balance in nature between animals and plants.Para.3If 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 s

17、pecies 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.The Black RobinBlack robins are the birds that humans

18、 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

19、Blues eggs,helped them to hatch,and took care of the 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

20、 they live.Case StudyNotesrobin n.知更鸟habitat n.栖息地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 and cats from the islands where they live.The case study showed that even in desperate situations,we can

21、 do something to help.In short,its never too late.4.What did people do in the case study to protect black robins?Which claim(s)did the case study support in the text?In the last 500 million years,there have been five mass extinction events on Earth.In the third event,which 1._ the“Great Dying”,90%to

22、 96%of all species 2._.Of course,species died out due to many causes.But nowadays,human activity 3._ all types of species that we 4._ for living.We need to 5._ to avoid the sixth mass extinction.We should 6._ to save endangered animals and plants,and 7._ special areas to 8._ them before the next ext

23、inction comes that may 9._ the entire species.die out be known as have affected depend on wipe out take steps take action set up take care of Complete the paragraph about extinctions using the correct form of the phrases below.is known asdied outhas affecteddepend ontake actiontake stepsset uptake care ofwipe outSummarywrite an essay to express your opinions on the sixth extinction.HomeworkLet her smileDont let her cry.