Unit3ConservationLesson1TheSixthExtinction知识点课件高中英语北师大版选择性

Unit3ConservationLesson1知识点by:EmilyTheTheSixthExtinctionExtinctions,whereentirespeciesarewipedout,arenotunusualinourEarth'shistory.Infact,over90percentofallspeciesthateverlivedarenowextinct.Inthelast500millionyears,therehavebeenfivetimeswhenlifeonEarthhasalmostended.Theseincludethe

thirdmassextinction,knownasthe“GreatDying”,彻底消灭，全部摧毁n.物种(单复数同形)

=as

amatteroffact事实上定从adj.灭绝的过去的现在完成时whichis定从whichkilled90%to96%ofallspecies.Andthefifthevent,which

occurred66millionyearsago,causedthedeathofthedinosaurs.Thereasonsforextinctionsarevaried.Accordingtoscientists,theyincludevolcaniceruptions,asteroidshittingtheEarthfromspace,changesinsealevels,thedecreaseoftheoxygencontent定从，修饰thethirdmassextinction非限制性定从

v.导致

n.原因；事业

vary

v.变化;variety

n.种类,多样化;various

adj.各种各样的火山喷发小行星现在分词做后置定语海平面含氧量oftheseaandglobalwarming.ManyscientistssaywearenowenteringtheEarth'ssixthmassextinction.Thistime,humanactivitywillbetoblame.Althoughitisnotunusualforspeciestodieoutnaturally,therateatwhichthisisnowhappeningiscauseforconcern.A2015studybyscientistswhowere全球变暖betoblame(forsth.)(对坏事)负有责任It+is+adj+forsb.+todosth.灭绝介词+关系代词”引导的定语从句，修饰therate；固搭：attherate以……速度担忧的原因定从basedatBrownUniversityandDukeUniversityintheUS,lookedathowquicklyspeciesdieoutduetonaturalcauses,thatis,the“backgroundextinctionrate”.Theyfoundthathumanactivityiscausingspeciestodieout1,000timesfasterthannormal.Thereisalonglistofreasonswhysomanyspeciesaredyingout:airadj.在……居住(或工作)思考，考虑，研究因为，由于=becauseof/owingto/thanksto背景灭绝率：是指地球正常的灭绝率，通常被认为是每100年里10000个物种中就有0.1到1个物种灭绝。大规模灭绝事件是指物种的消失速度远快于背景灭绝率，通常指的是不到280万年里，就大约有75%的物种消失。宾从why引导的定语从句，修饰reasons,why在从句中作状语。andwaterpollution,forestsbeingdestroyed,factoryfarmingandoverfishing.ItisclearthathumanactivityhasnegativelyaffectedallotherspeciesonEarth,includinganimalsandplants.Ifasixthmassextinctionoccurs,scientistswhohavestudiedtheissuebelieve

thatuptothreequartersofallspeciesonEarthcoulddieout.Ofcourse,aswe过度捕捞，over过于…；overproduction生产过剩工厂化养殖主从，it做形式主语vt.影响定从quartern.1/4；一刻钟宾从某人突然想到一个主意：Itoccurs/occurredtosbthat+句子.Itstrikes/strucksbthat+句子.as因为，由于+(原因状从)humansdependonsomanyspeciesforoursurvival,wewouldalsobeatriskofdyingout.Ourworldandourlivesdependonthebalanceinnaturebetweenanimalsandplants.Withoutforests,wewouldhavenoairtobreathe,andwithoutcleanwaterwewouldbeunabletosurvive.Canasixthextinctionbeavoided?Expertssaythatit依靠/赖；取决于n.生存，幸存有(做某事)的危险；riskyadj.有危险的，有风险的breathn.呼吸；takeadeepbreath深呼吸beabletodosth.能够做某事该句为含蓄条件句。介词短语Withoutforests和withoutcleanwater相当于条件，“wewouldhavenoairtobreathe”和“wewouldbeunabletosurvive”表示与现在事实相反的假设。avoid(doing)sth.避免(做)某事宾从isnotyettoolate,ifwetakeactionnow.Thiswouldmeanwehavetosignificantlychangethewaywelive.Forexampleweneedtotakestepstosaveendangeredspecies,includingsettingupspecialareaswhereplantsandanimalscanbeprotected.Weneedtochangehowweworkandtravelbyusingcleaner,morenaturalsourcesofenergy,suchaswind采取行动采取行动includedoingsth.包括做某事where引导的定语从句，修饰areas,where在从句中作状语andsolarenergy.Wealsoneedtoimproveourfarmingmethodstoreducewater,airandlandpollution.Inshort,ifwewanttosurvive,weneedtostopdestroyingtheplanetthat

weliveonandstarttoprotectit.太阳能减少……污染总之，简言之destroy-destroyed;n.destruction破坏；adj.destructive毁灭性的定从

TheBlackRobinBlackrobinsarethebirdsthathumanssavedfromextinction.In1980,therewereonlyfiveblackrobinsleftintheworld.TheyalllivedonasmallislandoffthecoastofNewZealand.Onlyoneofthosebirds,afemalecalledOldBlue,wasabletolayeggs.Wildlifeworkersbeganaprogrammeforraisingblackrobin定从非谓，做后置定语，被遗留下来的远离海岸的非谓，做后置定语，被称为……产卵，下蛋开始一项计划vt.饲养，培育chicks.TheyprotectedOldBlue'seggs,helpedthemtohatch,andtookcareofthechicks.Thankstotheirefforts,therearenowmorethan250blackrobins,andthepopulationisspreading.Tohelpthemsurvive,peo