2023学年完整公开课版Unit8Lesson22FamousDiscoveries教学

Unit8Lesson22FamousDiscoveriesThinkaboutitIfwelearnmoreaboutDNA,wewillbeabletotreatmorediseases.Isthisarealsituation?CanwelearnmoreaboutDNA?GrammarReadthepassageandunderlinethesentenceslikethis.IfwelearnmoreaboutDNA,wewillbeabletotreatmorediseases.Ifwedonotusethemcorrectly,theycancauseserioushealthproblems.

Ifwediscovermoreaboutthehumanbody,wecanhelppeoplelivelongerandbetterlives.Whichexpressestheresultiftheconditionhappens?Whichpartofthesentence,whichclause,expressesthecondition?Ifwediscovermoreaboutthehumanbody,wecanhelppeoplelivelongerandbetterlives.从句主句IfI______(have)time,I__________(visit)mygrandparents.Ifyou_____(have)anyquestions,you__________(ask)Kimforhelp.havewillvisithavecanask条件状语从句主要由if或unless引导。if是连词，意为“如果；假如”。unless，意为“除非；如果不”，通常可以和if...not互换使用。条件状语从句e.g.Ifitrainstomorrow,theywon’tgoout.Iwon’twriteunlesshewritesfirst.=Iwon’twriteifhedoesn’twritefirst.if引导的条件状语从句通常表示一种假设的条件，即如果从句的动作发生，则主句的动作有可能会发生。通常情况下，如果主句用一般将来时，if引导的条件状语从句用一般现在时。e.g.Ifitrains,I’llstayathome.如果主句是祈使句或者主句的谓语部分含有情态动词，if引导的条件状语从句也常用一般现在时。e.g.PleasetellTomaboutitifhecomesback.Youmuststudyhardifyouwanttogetgoodgrades.主句没有用一般将来时，而是用了一般现在时。这是条件状语从句运用时的一个特殊情况：如果句子表示“客观事实”，主句和从句通常都用一般现在时。e.g.Ifbabydogsareindanger,theirmotherattackspeople.条件状语从句结构时态主句+引导词+从句引导词+从句，主句主句将来时，从句现在时主句过去时，从句过去时主句祈使句，从句现在时主句情态动词，从句现在时Whatcan/willyoudoif....·thereisafire?·thereisanearthquake?·yourbikeisbrokenonyourwaytoschool?·yougetlost?PairWorkTalkaboutthediscoveriesinExercise2.Whichdoyouthinkisthemostimportant?GroupWorkExampleA:IthinkX-raysarethemostimportantdiscovery.B:BecausewithX-rays,doctorscanhelpfixbrokenbonesmoreeasily.C:…Peoplenowlivelongerbecauseofantibiotics.Readthetextagainandanswerthequestionsbelow.1.Whateffectdoantibioticshaveonhowlongpeoplelive?2.ScientistsdiscoveredDNAin1869.Howmanyyearslaterdidtheydiscoveritsstructure?3.WhatcanscientistsknowfromthemapofourDNA?84years.Ittellsthemagreatdealaboutwhatwegetfrom