北师大版（2019）选择性必修第一册Unit 3 Conservation Section Ⅳ　Grammar 教学课件(共27张PPT)

(共27张PPT)
Unit 3　Conservation
Section Ⅳ　Grammar
画出句子中的定语从句,并说明是限制性定语从句还是非限制性定语从句
1.These include the third mass extinction,known as the “Great Dying”,which killed 90% to 96% of all species.
2.The rate at which this is now happening is cause for concern.
which killed 90% to 96% of all species;非限制性定语从句
at which this is now happening;限制性定语从句
3.A 2015 study by scientists who were based at Brown University and Duke University in the US,looked at how quickly species die out due to natural causes.
4.There is a long list of reasons why so many species are dying out.
who were based at Brown University and Duke University in the US;限制性定语从句
why so many species are dying out;限制性定语从句
5.If a sixth mass extinction occurs,scientists who have studied the issue believe that up to three quarters of all species could die out.
6.We need to take steps to save endangered species including setting up special areas where plants and animals can be protected.
who have studied the issue;限制性定语从句
where plants and animals can be protected;限制性定语从句
7.If we want to survive,we need to stop destroying the planet that we live on and start to protect it.
that we live on;限制性定语从句
定语从句(4)　限制性和非限制性定语从句
一、结构
定语从句修饰主句中的名词成分(主语、宾语或者表语),其引导词的辨别方式在限制性与非限制性定语从句中没有区别。
限制性与非限制性定语从句主要区别如下
二、用法
1.当从句中缺少的成分为名词性成分时
2.当从句中缺少的成分为形容词性成分时
【即学即用】
单句语法填空
①My gardener,　　　　　　 is very pessimistic,says that there will be no apples this year.
②He is absorbed in work,　　　　　　 he often was.
③Dorothy was always speaking highly of her role in the play,
　　　　　　 made the others unhappy.
who
as
which
④These apple trees,　　　　　　 I planted three years ago,have not borne any fruit.
⑤The man 　　　　　　two sons had both died in the war was very poor.
⑥The car 　　　　　　crashed into me belonged to Paul.
which
whose
which/that
3.当从句中缺少的成分为状语时
【即学即用】
单句语法填空
①I met a famous professor in the hotel,　　　　　　 the meeting was held.
②He may have acute appendicitis,　　　　　　 which case he will have to be operated on.
where
in
③It now has 20,000 hectares of land,more than two-thirds
　　　　　　which are under cultivation.
④Mr Smith,　　　　　　 whom I have learned a lot,is a famous scientist.
⑤The reasons 　　　　　　so many species are dying out are related to human activities.
of
from
why