Unit3ConservationLesson1TheSixthExtinction知識(shí)點(diǎn)課件高中英語(yǔ)北師大版選擇性

Unit3ConservationLesson1知識(shí)點(diǎn)by:EmilyTheTheSixthExtinctionExtinctions,whereentirespeciesarewipedout,arenotunusualinourEarth'shistory.Infact,over90percentofallspeciesthateverlivedarenowextinct.Inthelast500millionyears,therehavebeenfivetimeswhenlifeonEarthhasalmostended.Theseincludethe

thirdmassextinction,knownasthe“GreatDying”,徹底消滅，全部摧毀n.物種(單復(fù)數(shù)同形)

=as

amatteroffact事實(shí)上定從adj.滅絕的過(guò)去的現(xiàn)在完成時(shí)whichis定從whichkilled90%to96%ofallspecies.Andthefifthevent,which

occurred66millionyearsago,causedthedeathofthedinosaurs.Thereasonsforextinctionsarevaried.Accordingtoscientists,theyincludevolcaniceruptions,asteroidshittingtheEarthfromspace,changesinsealevels,thedecreaseoftheoxygencontent定從，修飾thethirdmassextinction非限制性定從

v.導(dǎo)致

n.原因；事業(yè)

vary

v.變化;variety

n.種類(lèi),多樣化;various

adj.各種各樣的火山噴發(fā)小行星現(xiàn)在分詞做后置定語(yǔ)海平面含氧量oftheseaandglobalwarming.ManyscientistssaywearenowenteringtheEarth'ssixthmassextinction.Thistime,humanactivitywillbetoblame.Althoughitisnotunusualforspeciestodieoutnaturally,therateatwhichthisisnowhappeningiscauseforconcern.A2015studybyscientistswhowere全球變暖betoblame(forsth.)(對(duì)壞事)負(fù)有責(zé)任It+is+adj+forsb.+todosth.滅絕介詞+關(guān)系代詞”引導(dǎo)的定語(yǔ)從句，修飾therate；固搭：attherate以……速度擔(dān)憂(yōu)的原因定從basedatBrownUniversityandDukeUniversityintheUS,lookedathowquicklyspeciesdieoutduetonaturalcauses,thatis,the“backgroundextinctionrate”.Theyfoundthathumanactivityiscausingspeciestodieout1,000timesfasterthannormal.Thereisalonglistofreasonswhysomanyspeciesaredyingout:airadj.在……居住(或工作)思考，考慮，研究因?yàn)?，由?becauseof/owingto/thanksto背景滅絕率：是指地球正常的滅絕率，通常被認(rèn)為是每100年里10000個(gè)物種中就有0.1到1個(gè)物種滅絕。大規(guī)模滅絕事件是指物種的消失速度遠(yuǎn)快于背景滅絕率，通常指的是不到280萬(wàn)年里，就大約有75%的物種消失。賓從why引導(dǎo)的定語(yǔ)從句，修飾reasons,why在從句中作狀語(yǔ)。andwaterpollution,forestsbeingdestroyed,factoryfarmingandoverfishing.ItisclearthathumanactivityhasnegativelyaffectedallotherspeciesonEarth,includinganimalsandplants.Ifasixthmassextinctionoccurs,scientistswhohavestudiedtheissuebelieve

thatuptothreequartersofallspeciesonEarthcoulddieout.Ofcourse,aswe過(guò)度捕撈，over過(guò)于…；overproduction生產(chǎn)過(guò)剩工廠化養(yǎng)殖主從，it做形式主語(yǔ)vt.影響定從quartern.1/4；一刻鐘賓從某人突然想到一個(gè)主意：Itoccurs/occurredtosbthat+句子.Itstrikes/strucksbthat+句子.as因?yàn)?，由?(原因狀從)humansdependonsomanyspeciesforoursurvival,wewouldalsobeatriskofdyingout.Ourworldandourlivesdependonthebalanceinnaturebetweenanimalsandplants.Withoutforests,wewouldhavenoairtobreathe,andwithoutcleanwaterwewouldbeunabletosurvive.Canasixthextinctionbeavoided?Expertssaythatit依靠/賴(lài)；取決于n.生存，幸存有(做某事)的危險(xiǎn)；riskyadj.有危險(xiǎn)的，有風(fēng)險(xiǎn)的breathn.呼吸；takeadeepbreath深呼吸beabletodosth.能夠做某事該句為含蓄條件句。介詞短語(yǔ)Withoutforests和withoutcleanwater相當(dāng)于條件，“wewouldhavenoairtobreathe”和“wewouldbeunabletosurvive”表示與現(xiàn)在事實(shí)相反的假設(shè)。avoid(doing)sth.避免(做)某事賓從isnotyettoolate,ifwetakeactionnow.Thiswouldmeanwehavetosignificantlychangethewaywelive.Forexampleweneedtotakestepstosaveendangeredspecies,includingsettingupspecialareaswhereplantsandanimalscanbeprotected.Weneedtochangehowweworkandtravelbyusingcleaner,morenaturalsourcesofenergy,suchaswind采取行動(dòng)采取行動(dòng)includedoingsth.包括做某事where引導(dǎo)的定語(yǔ)從句，修飾areas,where在從句中作狀語(yǔ)andsolarenergy.Wealsoneedtoimproveourfarmingmethodstoreducewater,airandlandpollution.Inshort,ifwewanttosurvive,weneedtostopdestroyingtheplanetthat

weliveonandstarttoprotectit.太陽(yáng)能減少……污染總之，簡(jiǎn)言之destroy-destroyed;n.destruction破壞；adj.destructive毀滅性的定從

TheBlackRobinBlackrobinsarethebirdsthathumanssavedfromextinction.In1980,therewereonlyfiveblackrobinsleftintheworld.TheyalllivedonasmallislandoffthecoastofNewZealand.Onlyoneofthosebirds,afemalecalledOldBlue,wasabletolayeggs.Wildlifeworkersbeganaprogrammeforraisingblackrobin定從非謂，做后置定語(yǔ)，被遺留下來(lái)的遠(yuǎn)離海岸的非謂，做后置定語(yǔ)，被稱(chēng)為……產(chǎn)卵，下蛋開(kāi)始一項(xiàng)計(jì)劃vt.飼養(yǎng)，培育chicks.TheyprotectedOldBlue'seggs,helpedthemtohatch,andtookcareofthechicks.Thankstotheirefforts,therearenowmorethan250blackrobins,andthepopulationisspreading.Tohelpthemsurvive,peo