八年级下剑桥第3课课件.ppt

1、Unit 7 Disaster1、unfortunately /nftntli/不幸地不幸地2、mayor /me/市长市长3、absolutely /bslutl/绝对地绝对地4、rescue /reskju/拯救拯救5、damage /dmd/损害损害6、levee /lev/防洪堤防洪堤7、destroy /dstr/破坏破坏 8、huge /hjud/巨大的巨大的9、estimate /estmet/估计估计10、effect /fekt/影响影响How might they cause problems for people?sparrowsnakecockroach/kkrt/lo

2、cust /lkst/1.What insects is the 1.What insects is the text about?text about?2.How do the insects 2.How do the insects normally live?normally live?3.How can they become 3.How can they become dangerous for people?dangerous for people?4.Why are farmers afraid 4.Why are farmers afraid of them?of them?L

3、ocust Locust 蝗虫蝗虫On their own.On their own.独自独自When they form swarms.When they form swarms.They destroy the harvest They destroy the harvest and bring hunger.and bring hunger.A flying disasterA flying disasterEarthquakes.Floods.Earthquakes.Floods.Hurricanes.Tsunamis.It Hurricanes.Tsunamis.It seems t

4、hat every day we read seems that every day we read about at least one of these about at least one of these somewhere in the world.But somewhere in the world.But every year,somehere,another every year,somehere,another kind of disaster causes great kind of disaster causes great damage to plants and pe

5、ople.damage to plants and people.Its something much Its something much smaller and not so well-smaller and not so well-known as an earthquake known as an earthquake or a tsunami-its an or a tsunami-its an insectinsect called the called the locustlocust.昆虫昆虫蝗虫蝗虫The locust usually does The locust usua

6、lly does things alone-it lives things alone-it lives on its on its ownown and eats on its own.But,and eats on its own.But,sometimes,something sometimes,something changes the way nature changes the way nature works.When the number of works.When the number of locusts locusts increaseincreases s somewh

7、ere and there are somewhere and there are lots of plants to eat,the lots of plants to eat,the locusts get together in locusts get together in“swarmswarms”.s”.独自独自增加增加一大群一大群Perhaps the most Perhaps the most dangerous locust is the dangerous locust is the desert locust.It is found in desert locust.It

8、is found in Africa,the middle East,and Africa,the middle East,and Asia-in about 60 countries Asia-in about 60 countries altogetheraltogether.When desert.When desert locusts swarm,they bring locusts swarm,they bring problems to one-tenth of all problems to one-tenth of all the the humanshumans in the

9、 world.in the world.总共总共人类人类The numbers are The numbers are hugehuge and and frighteningfrightening.A swarm of desert.A swarm of desert locusts can be 1.200 km in locusts can be 1.200 km in size-size-imagineimagine an area that is an area that is over 20 kilometres wide and over 20 kilometres wide a

10、nd 50 kilometres long,full of 50 kilometres long,full of locusts!And there can be 50 locusts!And there can be 50 million locusts in each million locusts in each square square kilometrekilometre.巨大的巨大的令人害怕的令人害怕的想象想象平方千米平方千米Each locust eats its own Each locust eats its own weightweight in plants every

11、 day-so in plants every day-so a swarm of desert locusts can a swarm of desert locusts can eat more than 150 million eat more than 150 million kilos of food in one day.They kilos of food in one day.They can also fly very long can also fly very long distancedistances-in 1954 a swarm s-in 1954 a swarm

12、 of locusts from northwest of locusts from northwest Africa flew thousands of miles Africa flew thousands of miles to finally land in Great Britain!to finally land in Great Britain!重量重量距离距离Its Its no wonderno wonder that farmers that farmers in many countries of the in many countries of the world fe

13、ar the desert world fear the desert locust more than snakes locust more than snakes and and spiderspiders.Its the desert s.Its the desert locust that destroys the locust that destroys the harvestharvest and brings and brings hungerhunger to people all over the world.to people all over the world.难怪难怪

14、蜘蛛蜘蛛收获、收割收获、收割饥饿饥饿1.What do all the 1.What do all the disasters mentioned in disasters mentioned in the text the text have in commonhave in common?They cause damage to They cause damage to plants and people.plants and people.They are very small,they They are very small,they live on their own and liv

15、e on their own and they dont hurt anyone.they dont hurt anyone.2.Why is it 2.Why is it surprisingsurprising that that locusts can cause such locusts can cause such enormousenormous damage?damage?One-tenth.One-tenth.3.What 3.What proportionproportion of the of the worlds population can be worlds popu

16、lation can be in danger because of locust in danger because of locust swarms?swarms?比例、比重比例、比重4.What makes the 4.What makes the desert locust so desert locust so dangerous?dangerous?They swarm in huge They swarm in huge numbers and they can numbers and they can eat their own weight in eat their own

17、weight in plants every day.plants every day.5.Why can locusts bring 5.Why can locusts bring death to lots of people?death to lots of people?They destroy the They destroy the harvest so people die harvest so people die of hunger.of hunger.1、insect /nsekt/昆虫昆虫2、on ones own 独自独自3、increase /nkris/增加增加4、swarm /swm/一大群一大群5、altogether /ltge/总共总共6、frightening /fratn/令人害怕的令人害怕的7、imagine /mdn/想象想象 8、distance /dstns/距离距离9、no wonder 难怪难怪10、harvest /hvst/收获、收割收获、收割