1、zUnit 3ConservationLesson 1-(2)zPart 1Lead inzLets review the passage according to the following information.Lead inl Background history of the sixth extinction.l Causes of the sixth extinction.l Effects of the sixth extinction.l What we can do to prevent the sixth extinction.zShow time!Lead inzPart
2、 2Reading comprehensionzLets read!Read and think Extinctions,where entire species are wiped out,are not unusual in our Earths 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.Th
3、ese 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 hitt
4、ing 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 Earths sixth mass extinction.This time,human activity will be to blame.Although it is not unusual for species to die out naturally,the rate at w
5、hich 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
6、 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.zLets read
7、!Read and think 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 th
8、e 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.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
9、 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 farmin
10、g 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.zExtinctions,where entire species are wiped out,are not unusual in our Earths history.wipe out:彻底毁灭wipe.with.用擦wipe sth.away/off/up 擦掉/擦净某物wip
11、e sth.off/from.把某物从处擦掉wipe sth.from/off ones mind/memory 有意忘记某事整个物种灭绝，在我们地球的历史上并不罕见。Useful expressions非限制性定语从句，先行词extinctions，关系副词wherezIn fact,over 90 percent of all species that ever lived are now extinct.ever:l“在任何时候”，有时可与always替换，表示“始终，一直”Honesty ever pays.l 可出现在过去时态或完成时态的疑问句中。Did you ever see s
12、uch a grand parade?l 在疑问句中，长用来加强语气。What ever do you want?事实上，有史以来90%以上的物种现已灭绝。Useful expressionszAnd the fifth event,which occured 66 million years ago,caused the death of the dinosaurs.occur:用作动词基本含义是“呈现在视野、思想、意识中”。一般只用作不及物动词，含有“出乎意料”的意味。The explosion occured during an exercise near the town.有时还可用作
13、系动词，接形容词作表语，表示“存在”。Few metals occur free.指“想到”时，后面跟介词to。It occured to me to visit my teacher.第五次事件发生在6600万年前，导致恐龙死亡。Useful expressionszThe reasons for extinctions are varied.varied:adj.“各种各样的，形形色色的”varitey:n.多种样式；不同种类；多变性a variety of styles 各种风格variety in ones lifestyle 生活方式的多样化variety show 综艺节目vary
14、 vi.&vt.变化，改变various adj.各种各样的=a variety of物种灭绝的原因多种多样。Useful expressionsz.the decrease of the oxygen content of the sea and global warming.decrease:名词，表示“减少；减少的量”动词，表示“减少”。decrease in 在减少decrease to+数字 下降到decrease by+/分数、百分数或其他表示数量的词 下降了oxygen content:氧含量海洋含氧量的减少和全球变暖。Useful expressionszThis time,h
15、uman activity will be to blame.blame:责怪，指责be to blame(for sth.)应该为（某事）负责人blame sth.on sb./sth.把某事归咎于某人/某事blame sb.for(doing)sth.因（做）某事而责备某人put/lay/place the blame(for sth.)on sb.把某事归咎于某人这一次，人类活动将是罪魁祸首。Useful expressions是主动形式表示被动zAlthough it is not unusual for species to die out naturally,the rate at
16、 which this is now happening is cause for concern.die out:消失；绝迹、灭绝die away:（声音、风、光等）逐渐消失die off:（一群生物）相继死去die down:（慢慢地）熄灭；平息下来rate:比率at the rate of.以之比率虽然物种自然灭绝并不罕见，但现在这种情况发生的速度令人担忧。Useful expressionsz.that is,the“background extinction rate”.that is:也就是说；即（用于纠正之前说过的内容）=that is to say即“背景消光率”。Useful
17、 expressionszThey found that human activity is causing species to die out 1,000 times faster than normal.1000 times faster than:比快一千倍表示倍数句式：A is.times as long/wide/high/large/deep.as B.The dictionary is almost five times as expensive as that one.A is.times longer/wider/higher/deeper.than B.The new s
18、treet is 3 times wider than the old one.A is.times the length/width/height/size/depth.of B.China is almost twice the size of their country in area.A is.times+what 从句 The dictionary costs three times what it did before.A has increased/decreased/reduced/gone up/risen by.times.The price of meat has gon
19、e up by three times.他们发现人类活动导致物种灭绝的速度比正常情况快1000倍。Useful expressionszThere is a long list of reasons why so many species are dying out:air and water pollution,forests being destroyed,factory farming and overfishing.destroy:破坏；毁掉。destroy sb.毁掉某人（的一生）be destroyed by fire被大火烧毁destruction 破坏destroyer 破坏者
20、overfishing:过度捕捞over-:前缀，表示过度Useful expressions这么多物种灭绝的原因有很多：空气和水污染、森林被破坏、工厂化养殖和过度捕捞。zIt is clear that human activity has negatively affected all other species on Earth,including animals and plants.It is clear that:很明显，it作形式主语，该句为主语从句affect:影响；感染；打动be affected by.被所打动/影响be affected with.患上疾病effect:效
21、果；作用；影响have an effect on/upon.对有影响/效果cause and effect因果come into effect 开始生效；使生效put/bring.into effect实施；使生效很明显，人类活动对地球上所有其他物种，包括动物和植物，都产生了负面影响。Useful expressionszWithout forests,we would have no air to breathe,and without clean water we would be unable to survive.without和no构成双重否定，用以加强语气。without还可以表示
22、“如果没有”，用于虚拟语气，相当于but for。Without his wartime experiences,Hemingway wouldnt have written his famous novel A Farewell to Arms.没有森林，我们就没有空气可以呼吸，没有干净的水，我们就无法生存。Useful expressionszExperts say that it is not yet too late,if we take action now.take action:采取行动专家表示，如果我们现在就采取行动，现在还为时不晚。Useful expressionszFor
23、 example,we need to take steps to save endangered species,including setting up special areas where plants and animals areas where plants and animals can be protected.take steps:采取措施例如，我们需要采取措施保护濒危物种，包括建立特殊的动植物保护区和动植物保护区。Useful expressionszIn short,if we want to survive,we need to stop destroying the
24、 planet that we live on and start to protect it.in short:简而言之简而言之，如果我们想要生存，我们需要停止破坏我们赖以生存的星球，并开始保护它。Useful expressionszPracticeUse the adjectives and nouns to make meaningful expressions.Then use each expression to make a sentence.Write the sentences in the space provided.zPracticeUse the adjectives
25、 and nouns to make meaningful expressions.Then use each expression to make a sentence.Write the sentences in the space provided.1.Crucially,could it lower the global average temperature of the earth in time to avoid killing millions more people,more animals and indeed entire species?2.The panda amba
26、ssadors will visit a dozen countries to promote the protection of the endangered animal.3.They have had a significant change in policy on paternity leave.4.They are looking at ways of reducing the waste of natural resources.5.Well,today we are witnessing a sixth mass extinction.6.Solar energy can be
27、 transformed into power.zPracticeComplete the paragraph about extinctions using the correct form of the phrases below.ABCDFGHEIzPracticeLets check!AB is known asCDFGHEIA died outC has affectedDG/FG/FHIEz定语从句Focus on language限制性定语从句&非限制性定语从句zFocus on languageThe girl who is playing tennis is my frien
28、d.This is the place where I hid the key.限制性定语从句修饰名词或代词，表明所修饰的是哪个人或物。zFocus on languageMy friend,who is playing tennis,comes from Ethiopia.The building,where an important conference is being held,is in the centre of the city.非限制性定语从句提供句子意义以外的额外信息，要用逗号隔开。zFocus on languageIt is snowing heavily,which m
29、akes children feel excited.The river is seriously polluted,which has caused much public attention.非限制性定语从句中的关系代词可以指代整个句子。z1 Extinctions,where entire species are wiped out,are not unusual in our Earths history.2 These include the third mass extinction,known as the“Great Dying”,which killed 90%to 96%o
30、f all species.3 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.4 If a sixth mass extinction occurs,scientists who have studied the issue believe that up to three quarters of all species on Earth
31、could die out.5 We need to take steps to save endangered species,including setting up special areas where plants and animals can be protected.PracticeRead the sentences and discuss which word(s)the clauses(in italics)refer to.2/3/41/2zPracticeUnderline the relative clauses in the sentences and decid
32、e if they are defining(D)or non-defining(ND).Translate them into Chinese.Discuss the difference in meaning between the two types of relative clauses.DDNDNDNDzGroup WorkChoose two or three environmental problems that are caused by human activity.Offer solutions.Try to use relative clauses where appro
33、priate.zPart 3HomeworkzRecite the key words and expressions.Write the sentences to match the endings.Example _,which was quite a surprise.My painting won the first prize,which was quite a surprise.1 _,which made me angry.2 _,who isnt very kind at all.3 _,which I really liked.4 _,whose cousin is coming to town.HomeworkzExample _,which was quite a surprise.My painting won the first prize,which was quite a surprise.5 _,which changed my plans for the future.6 _,where the storms can be terrible.7 _,which scared me to death.8 _,which I borrowed from my friend.Homework
