高中英语外研版 (2019)选择性必修 第二册Unit 5 A delicate world教学演示课件ppt

这是一份高中英语外研版 (2019)选择性必修 第二册Unit 5 A delicate world教学演示课件ppt，共42页。PPT课件主要包含了素养导航，晨读晚诵，重点短语 ，重点句式，答案C ，答案B ，答案A ，答案D ，重点词汇，随堂练习等内容，欢迎下载使用。

Why Is Eclgical Balance Imprtant?Ecsystems are essential① t ur well-being and prsperity② as they prvide us with fd,clean air and fresh water.Ecsystems als represent an exceptinal surce f utdr recreatin pprtunities.
Eclgical balance is imprtant fr the cntinued survival and existence f rganisms as well as the stability f the envirnment.The balance in the ecsystem,which must be maintained,may be disturbed as a result f natural hazards,the unexpected death f a particular species,man-made causes r the intrductin f new species t the ecsystem. 
Eclgical balance is a cnditin f a dynamic③ balance within an ecsystem in which the species,genetics and the ecsystem diversity remain in a stable state irrespective f the gradual variatins④ thrugh natural successin.The ecsystem stability is characterized by tw prperties: resilience and resistance.Resilience is a prperty that is manifested in an ecsystem when rganisms are killed r weakened.Resilience als refers t the rate at which the density f a ppulatin in an ecsystem cmes back t the equilibrium after a particular disturbance.Resistance stands fr the ptential f an ecsystem t prevent the animal ppulatin and trees frm giving in t stresses such as high pllutin r drught.
Diversity⑤ is maintained when rganisms interact,and enhancing r destrying a specific species in an ecsystem may affect the entire ppulatin density ver time.Sme species,such as the sea tter (水獭),play a significant rle in maintaining eclgical balance and are knwn as keystne species.词海拾贝①essential adj.基本的;必要的②prsperity n.繁荣;成功③dynamic adj.动态的④variatin n.变化;变异⑤diversity n.多样性
典句欣赏The balance in the ecsystem,which must be maintained,may be disturbed as a result f natural hazards,the unexpected death f a particular species,man-made causes r the intrductin f new species t the ecsystem.译文:我们必须维持的生态系统平衡可能会被自然灾害、某特定物种的意外死亡、人为原因或新的物种的引进等因素所毁坏。分析:本句包含情态动词的被动语态的用法,另外里面还包含which引导的一个定语从句。as a result f 后接了并列的四个宾语。
探究思辨1.Why is eclgical balance imprtant?2.Hw can human beings keep eclgical balance?答案:1.Eclgical balance is imprtant fr the cntinued survival and existence f rganisms as well as the stability f the beings must pay mre attentin t natural hazards,the unexpected death f a particular species,man-made causes r the intrductin f new species t the ecsystem.
Sectin A　Starting ut & Understanding ideas
Ⅰ.知识体系图解重点词汇
1.　　　　　 n. 栖息地 2.　　 　　　 adv.后来,随后 3.　　　　　 n.胃口,食欲 4.　　　　　 v.(使)大大增加,(使)倍增 5.　　　 　　 n.保护 6.　　　　　 v.(使)变小;(使)减少 7.　　　　　 n.夹子;陷阱 8.　　　　　 v.突然增加 9.　　　　　 n.事件 10.　　　　　 v. 应该做;对……负有……的义务
habitat　subsequently　appetitemultiply　cnservatin　decrease　trapexplde　incident　 we　
11.halfway adj.　　　　　　 12.dramatically adv.　　　　　　 13.inhabitant n.　　　　　　 14.ersin n.　　　　　　 15.chas n.　　　　　　 16.virus n.　　　　　　 17.immunity n.　　　　　　 18.cllapse v.　　　　　　 19.substantial adj.　　　　　　 20.　　　　　n.生态;生态学→　　　　　adj.生态的,生态学的 
中间的,半途的显著地　栖居的动物　侵蚀　大混乱;紊乱病毒　免疫力　倒坍;塌下　大量的,多的
eclgy eclgical
1.　　 　　接管;接收 2.　　　　灭绝 3.　　　　结果是 4.　　 　　参加 5.　　 　　想出;提出 6.　　　　欠……;把……归因于;把……归功于 7.be native t　　　 　 　　 8.ut f cntrl　　　　 　　 9.remve frm...　　　　 　　 10.in cnsequence 　　　　 　　 11.r s 　　　　 　　 
take ver　die ut　turn utparticipate in　cme up with　
原产于;源于……　失控　从……移除　因此;结果　大约
1.Nr wuld they fail t imagine hw its native inhabitants,including ryal penguins,king penguins and elephant seals,existed in perfect harmny with their natural habitat fr thusands f cats in cnsequence turned their attentin — and their stmachs—back t the native birds,killing up t 60,000 each year.
Ⅱ.阅读导学A.划分部分,匹配大意Part 1(Para　　　　　)　　A.The island’s mre recent histry is a tragic stry. Part 2(Paras　　　　　)B.Macquarie Island enjys a wild and natural beauty. Part 3(Para　　　　　)C.There are sme measures t deal with the prblem. 
答案:Part 1:Para 1 B　Part 2:Paras 2-5 APart 3:Para 6 C
B.根据课文内容,选择正确答案1.Accrding t the passage,which f the fllwing is TRUE?A.Macquarie Island lies in the Antarctic green grass is in harmny with the bare Island is a UNESCO Wrld Heritage fail t understand hw its native inhabitants live with the habitat animal came t Macquarie Island first?A.Cats.B.Rabbits. C.Mice and rats.D.Dgs.
3.When did Macquarie Island becme an fficial nature reserve?A.In 1891.B.In the 1970s. C.In the 1980s.D.In were the dgs intrduced t the island?A.T decrease the number f kill the catch the diversify the f the fllwing is nt Macquarie Island’s prblem?A.Mice.B.Rabbits. C.Rats.D.Birds.
1.But althugh the virus caused the rabbit ppulatin t decrease frm 130,000 t arund 10,000,it als meant less fd fr the cats.但是虽然病毒导致兔子的数量从十三万减少到了一万,但是这也意味着猫的食物变得更少了。(p.51 )【词汇精讲】decrease v.减少　n.减少,缩减These measures will help decrease the cst f prductin.这些措施有助于降低生产成本。There is a sudden decrease in the species.物种急剧减少。
【词汇拓展】decrease by...减少了……(指减少的差值)decrease t...减少到……(指减少后的最终结果)decrease 从……减少到……n the decrease在减少
The traffic accidents in the city decreased by 30% last year.该城市去年交通事故减少了30%。The ppulatin decreased t 1 millin last year.人口去年减少到100万。Bth unemplyed,the cuple had t decrease their husehld expenses frm $1000 t $500 per mnth.夫妇俩都失业了,每月的家庭开支不得不从1000美元减少到500美元。Is yur prductin n the decrease?你们的产量在减少吗?
【微写作】The number f the cnsumers wh use ur prducts is n the decrease.Therefre,we have t decrease ur budget f next year frm $1000,000 t $80,000,which means it will decrease by 20%.
2.In the 1980s,traps and dgs were used t catch the cats.在二十世纪八十年代,陷阱和狗被用来抓猫。(p.51)【词汇精讲】trap名词,意为“陷阱;圈套;计谋;夹子”;动词,意为“诱捕;设陷阱;困住”。The fx culd nt be easily trapped by the farmer.那只狐狸不会轻易落入农夫的陷阱。Sme wmen see marriages as traps.有些女性把婚姻看作是陷阱。
【词汇拓展】set a trap设陷阱be caught in a trap落入圈套;落入陷阱be trapped in...困在……里;陷入……Set a trap ver that muse hle.把夹子放在那个鼠洞上面。He was trapped in a n-win situatin.他陷入必败的处境。【微写作】Last year,Hngxing Farm suffered a lt frm mice.The wner f the farm set a lt f traps everywhere in the farm.Finally,the majrity f mice were trapped in the traps.
3.It turned ut that they develped an immunity t the virus,and their numbers explded nce again.结果是它们形成了对病毒的免疫力,它们的数量再次激增了。(p.51)【词汇精讲】explde动词,意为“爆发;激增;(使)爆炸;突然(发出巨响,活跃起来,迸发感情)”。Bmbs were explding all arund the city.城里到处都响起炸弹的爆炸声。These fields are abut t explde with innvatin.这些领域将会创新大爆发。
【词汇拓展】explsin n.爆炸;爆发;激增explde with anger勃然大怒One hundred peple were injured in the explsin.有100人在爆炸中受伤。【易混辨析】explde/burst/eruptEvery time they met,Mr.Black explded with anger.每次他们见面,布莱克先生都会非常生气。
4.This interventin is a lng,much-delayed ending t a sad stry,but we humans we it t the island t give it a happy ending.这种干涉是一个悲伤的故事的拖延已久的结局,但是我们人类欠这个岛一个幸福结局。(p.51)【词汇精讲】we是动词,意为“欠(钱、账、人情等);归功于;应感谢”。Yu must pay me what yu we.你必须把你欠我的还给我。He wes his success t hard wrk.他把他的成功归功于勤奋工作。
【词汇拓展】we sth.t sb.欠某人某物we sb.an aplgy该向某人道歉we sb.a favur欠某人一个人情把……归功于……;应感激……wing adj.欠着的;未付的wing t=because f=n accunt f=due t 因为;由于
She still wes ￡3,000 t her father.她还欠她父亲3,000英镑。I think maybe we we yu an aplgy.我认为我们应向你道歉。Mary will take care f the baby—she wes me a favur.玛丽会照看孩子的——她欠我一个人情。Owing t the rain,the match was cancelled.由于大雨,比赛被取消了。
1.Nr wuld they fail t imagine hw its native inhabitants,including ryal penguins,king penguins and elephant seals,existed in perfect harmny with their natural habitat fr thusands f years.他们也会想象出岛上的居住者,包括皇家企鹅、帝企鹅、象海豹,几千年来与它们的自然栖息地和谐共处。(p.50)
【句式分析】nr 位于句首时,句子要使用部分倒装。(1)部分倒装是把be动词/助动词/情态动词提到主语的前面,即助动词/情态动词/be动词+主语+谓语动词。(2)否定词位于句首时要部分倒装,高考常考的这类词汇有:never,nt,nr,neither,seldm,hardly,nwhere,little,nt until,by n means,in n sense,at n time等。Tina wuldn’t agree with me.Nr wuld she discuss with me.蒂娜不会同意我的观点,她也不会和我讨论。I’ve tried very hard t imprve my English.But by n means is the teacher satisfied with my prgress.我已经非常努力地提高我的英语水平,但老师一点也不满意我的进步。Nt until the child fell asleep did the mther leave the rm.直到孩子睡着了,妈妈才离开房间。
2.The cats in cnsequence turned their attentin — and their stmachs—back t the native birds,killing up t 60,000 each year.结果猫把猎食目标转回到当地的鸟类身上,每年杀死多达六万只。(p.51)【句式分析】该句子中killing up t 60,000 each year为动词-ing短语作结果状语,表示“预料、情理之中”的结果。Unfrtunately his father died,leaving the family even wrse ff.不幸的是,他的父亲去世了,使得家境更加贫困。The news shcked the public,leading t great cncern abut students’ safety at schl.这条新闻使广大民众感到很震惊,引起了人们高度关注在校学生的安全。
Ⅰ.课文语法填空Macquarie Island is a UNESCO Wrld Heritage Site.The green grass and bare rck cntrast 1.　　　　　(dramatical),2.　　　　　(give) it a wild and natural beauty.The island’s recent histry 3._________　　　　　(tell) a tragic stry.In 1980 4.　　　　　 humans arrived n the island,they brught rats and 5.　　　　　(muse),6. 　　　　　 ate birds’ eggs and attacked baby birds.Later,cats and rabbits 7.　　 　　　(intrduce) t the island,making parakeets die ut.Experts felt it necessary 8.　　　　　 (remve) the rabbits,but cats had t eat birds.In the 1980s,traps and dgs were used t catch the cats.
dramatically
were intrduced
9.　　　　　the disappearance f cats,the mice,rats and rabbits started t increase,which led t a serius result.It was clear that the prblem needed 10.　　　　　(slve).Peple are taking sme steps t give the island a happy ending.