Unit3ConservationLesson1TheSixthExtinctionGrammar课件高二英语北师大版选择性.pptx

Unit3Lesson1TheSixthExtinctionGrammar

新课导入观察下列两组句子。Thisisthehousewhichweboughtlastmonth.Thehouse,whichweboughtlastmonth,isverynice.Helikestoreadbookswhicharewrittenbyforeignwriters.Theseappletrees,whichIplantedthreeyearsago,havenotanyfruit.

课堂学习RelativeClause定语从句Definingrelativeclause限制性定语从句Non-definingrelativeclause非限制性定语从句

1.限制性定语从句从句必不可少，否则先行词的意思不明确，主句也不完整，与先行词之间不用逗号。例句：Maryisagirlwhohaslonghair.I’dliketoseethefilmsthatarejustonshow.

2.非限制性定语从句对先行词起补充说明或描绘作用，没有它不会影响先行词或主句意思的完整性。从句一般用逗号同主句分开。例句：George,whoismyclassmate,haswonascholarship.Lucy,whosefatherisafencer,isenthusiasticaboutsport.

3.限制性定语从句和非限制性定语从句的区别。限制性定语从句非限制性定语从句1.从句与先行词的关系对先行词起修饰作用对先行词起补充说明作用2.标点从句和主句之间不用逗号分开从句和主句之间通常用逗号分开

3.关系代词指人who(that),whom;指物which(that);人和物whose关系代词在从句中作宾语可以省略指人who(作主语),whom(作宾语);指物which;人和物whose关系代词一般不可省略4.修饰从句只修饰名词或代词从句可以修饰名词或代词也可以修饰整个句子限制性定语从句非限制性定语从句

随堂练whowhoaswhy

Readthesentencesanddiscusswhichword(s)theclauses(initalics)referto.81.Extinctions,whereentirespeciesarewipedout,arenotunusualinourEarth’shistory.()2.Theseincludethethirdmassextinction,knownasthe“GreatDying”,whichkilled90%to96%ofallspecies.()referstoextinctionsrefersto“GreatDying”

3.A2015studybyscientistswhowerebasedatBrownUniversityandDukeUniversityintheUS,lookedathowquicklyspeciesdieoutduetonaturalcauses.()4.Ifasixthmassextinctionoccurs,scientistswhohavestudiedtheissuebelievethatuptothreequartersofallspeciesonEarthcoulddieout.()5.Weneedtotakestepstosaveendangeredspecies,includingsettingupspecialareaswhereplantsandanimalscanbeprotected.()referstoscientistsrefe