高中英语外研版 (2019)选择性必修 第二册Unit 5 A delicate world优质课件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优质课件ppt，共22页。

It as an empty bjectLk at the sentences and answer the questins. Sentences (a) and (c) are frm the reading passage. 1　What des “it” refer t in sentences (a) and (c)?
a　N visitr wuld think it surprising that the island is a UNESCO Wrld Heritage Site. b　N visitr wuld think that the island being a UNESCO Wrld Heritage Site is surprising. c　Experts felt it necessary t cme up with a plan t remve all the rabbits frm the island. d　Experts felt t cme up with a plan t remve all the rabbits frm the island was necessary.
“It” in sentence (a) refers t “the island is a UNESCO Wrld Heritage Site”. “It” in sentence (c) refers t “t cme up with a plan t remve all the rabbits frm the island”.
It as an empty bjectLk at the sentences and answer the questins. Sentences (a) and (c) are frm the reading passage. 2 　What is the difference between the sentences in each grup?
When the bject f a sentence is a that-clause (b) r an infinitive (d), we smetimes use “it” as an empty bject and put the real bject later t keep balance. Fr example, sentence (a) uses “it” as the empty bject f “think”, referring t the real bject: “the island is a UNESCO Wrld Heritage Site”. Sentence (b) uses that-clause as the bject f “think”.
Rewrite the underlined parts using it as an empty bject. The red-eared slider, a species f freshwater turtle, is native t the Suthern United States and Nrthern Mexic. Due t its cute appearance, many peple think keeping this turtle as a pet is a gd idea. Recent years have seen mre and mre pet sliders escaping r being released frm hmes, and sme wners believe t release them int the wild is n big issue. These days, peple have fund t release these turtles int the wild is a threat t ther species. Experts cnsider wners keeping their pets in an enclsed area imprtant, and anyne unable t keep their pets shuld take them t an apprpriate animal shelter.
many peple think it a gd idea t keep this turtle as a pet
Experts cnsider it imprtant fr wners t keep their pets in an enclsed area
believe it n big issue t release them int the wild
peple have fund it a threat t ther species t release these turtles int the wild
Lk at the pictures f the Saihanba Natinal Frest Park and describe its changes using it as an empty bject where apprpriate.
it 作形式宾语it 作形式宾语时，代替作真正宾语的动词不定式、动名词、从句，把真正的宾语置于宾语补足语之后。it 作形式宾语的常用句式有：（1）主语+find/think/feel/make/cnsider/believe+it +n./adj.（+fr/f sb.）+t d/that...。其中fr/f 引出不定式的逻辑主语。I dn’t feel it difficult t understand English. 我觉得理解英语并不难。He makes it a rule never t brrw mney. 他的规矩是从不向别人借钱。They fund it pleasant that they wrked with us Chinese.他们发现与我们中国人一起工作很愉快。（2）主语+find/think/feel/cnsider/believe+it+n use/n gd+ding sth.。D yu think it any gd trying again? 你觉得再试一次有用吗？
（ 3）有些动词如enjy，like，dislike，lve，hate，prefer，appreciate等，短语动词如rely n，see t，lk t，insist n，stick t，depend n，answer fr， granted 等，后面通常先接it 作形式宾语，然后再接when，if 或that 引导的从句。I hate it when my mther asks me t eat eggs. 我讨厌母亲要我吃鸡蛋。I wuld prefer it if yu didn’t tell anyne. 我希望你别告诉任何人。Yu may rely n it that he’ll cme t meet yu. 你放心，他会来接你的。I can’t answer fr it that he will cme. 我不能保证他会来。I tk it fr granted that he wuld help us. 我想当然地认为他会帮助我们。
◆单句语法填空（1）N matter where he is，he makes 　　　　　 a rule t g fr a walk befre breakfast.（2）［词汇复现］I’d appreciate it 　　　　　 yu culd help me figure ut this prblem.（3）As a dctr，I cnsider it my duty 　　　　　（cure） the patients f their diseases.（4）I dn’t think 　　　　　 pssible t master a freign language withut much memry wrk.（5）I think it n use 　　　　　（urge） him t give up smking.（6）He tk it fr granted 　　　　　 he wuld pass the exam，but he failed it.◆完成句子（7）The chairman 　　　　　　　　 　　　（认为它是必要的） t invite Prfessr Smith t speak at the meeting.
thinks/thught it necessary
EcsystemsLk at the diagram and answer the questins. Pay attentin t the wrds and expressins in bld.
EcsystemsLk at the diagram and answer the questins. Pay attentin t the wrds and expressins in bld.1　What des the diagram shw? 2　What are the relatinships between the living things?
The diagram shws a fd chain—the cnnectin between the living things.
The living things are clsely cnnected with each ther by the fd they eat. Secndary cnsumers prey n primary cnsumers, primary cnsumers feed n prducers, and prducers absrb light frm the sun, and water and disslved nutrients frm the sil, which are prvided by decmpsers.
Cmplete the passage with the crrect frm f the wrds and expressins in Activity 5.
In a wdland ecsystem, trees and ther plants are prducers. They 1__________ water, and take in nutrients frm the sil and energy frm the sun. Insects are an example f a primary cnsumer. They 2__________ the prducers t prvide fd fr them, and are 3__________ by secndary cnsumers: small mammals and birds. They 4__________ the primary cnsumers. Wrms, fungi and bacteria are decmpsers. They 5__________ animal waste and the remains f living things. The chemicals these decmpsers 6__________ fertilise the sil and give the plants the nutrients they need t grw.
　　absrb　　disslve nutrients　　rely n　　prvide energy　　　　　　　feed n　　prey n　　break dwn　　release
Listen t the cnversatin and chse the true statements.1　Bees are very imprtant t ur fd supply because they prvide hney.2　The bee ppulatin is declining. 3　Withut bees, humans wuld die ut.4　All human crps depend n bees fr pllinatin. 5　If bees became extinct, ther insects culd pllinate enugh crps.6　Humans are respnsible fr the decline in the bee ppulatin.
Listen again and cmplete the flw chart.
A cmbinatin f things damages bee habitats, mainly 1________________________.
The bee ppulatin is 2___________________. Accrding t statistics, bee numbers in the US 3__________________ in just ne year.
Withut bees, crps wuld 4____________________. 5_______________ wuld nt be able t cmpensate fr the lss f bees, because 6____________________________________ f the species f crps.
Animals that live n the crps 7_______________.
Humans have nthing t eat and die ut.
pesticides and climate change
declining very quickly
have fallen by 17%
be unable t reprduce
Other insects
bees are respnsible fr pllinating abut 70%
wuld die ut
Cmplete the bxes with the expressins frm the cnversatin.
Yu must be kidding! I dn’t believe it! It’s a fact!Dn’t frget yu sure it ut fr t statistics...
Yu must be kidding!I dn’t believe it!Are yu sure
It’s a fact!Dn’t frget it ut fr t statistics...
Language pints
核心词汇教材原句p.54 They feed n green plants. 它们以绿色植物为食。1 feed n （动物）以……为食It turned ut that the cats，which had fed n rats and mice，turned their appetites t native birds. 结果，曾经以大鼠和小鼠为食的猫把胃口转向了当地鸟类。［词汇复现］【归纳拓展】 把……喂给…… 用……喂……（用大量食物）养肥，养壮be fed up with= be tired f= be bred with 对……厌烦We feed grass t sheep.=We feed sheep n/with grass. 我们用草喂羊。【误区警示】feed n 主要指动物“以……为食”，其宾语为食物；live n 指人“以……为主食”“靠……生活”，其宾语为食物、金钱或某人，也可指动物“以……为食”。He was earning just enugh mney t live n. 他挣的钱刚够维持生活。
◆单句语法填空(1)The by is feeding grass _______the gat.=The by is feeding gat _________ grass.(2)She felt exhausted and a bit fed _______.(3) They feed mstly _______ insects and small reptiles，but als eat fish and frgs.(4) He was already fed up _______ ding the same thing again and again.◆完成句子(5)Actually，I have been_________________________________ （厌烦） his speech.(6)It is difficult fr him t_____________（靠……生活）such a small salary.
fed up with/tired f/bred with　
教材原句p.54 Decmpsers break dwn dead animal and vegetable matter int nutrients. 分解者把死去的动植物分解成营养物质。2 break dwn（使）分解；（机器或车辆）出故障，坏掉；（身体）垮掉，被搞垮；消除，驱除（人与人之间的隔阂等）Enzymes in the stmach break ur fd dwn int useful substances.胃中的酶把我们的食物分解成有用的物质。Our car brke dwn all f a sudden n the rad. 我们的车突然在路上出故障了。If Tim carries n wrking like this，he’ll break dwn sner r later.如果蒂姆继续这样工作，他的身体迟早会垮掉。We shuld wrk tgether t break dwn the barrier between races.我们应该共同努力消除种族之间的隔阂。［词汇复现］【归纳拓展】break up 破裂；结束；解散 break int 强行闯入；突然开始break in 闯入；插嘴 break away（frm） 脱离；逃脱break thrugh 取得突破 break ut（战争、火灾等）突然发生，爆发
◆单句语法填空(1) Water can be brken 　　　　　 int hydrgen and xygen.(2) The river was cvered with ice，which culd smetimes break 　　　　　 withut warning.(3) A big fire brke 　　　　　 last night and its cause is being lked int.(4) When he gt hme，he fund his huse brken 　　　　　.(5) Burglars brke 　　　　　 thrugh the bedrm windw.(6)［词汇复现］They brke away 　　　　　 the natinal unin and set up their wn lcal rganizatin.