高中英语 Unit4Exploring plantsListening课件 新人教选修9.ppt

Listening,1.How would you describe each plant?What do you think is unusual about each plant?2.One of the pictures shows pitcher plants and another shows“living stones”.Which picture shows which plant?The name of the plant in the other picture is Rafflesia.,Listening on P36,Look carefully at the photos of the plants and answer the questions.,living stone,Rafflesia,pitcher plants,Pitcher plant,Now listen to Mark,Gordon and Andrea telling their class about these plants.Which student talks about which plant?,Mark,Pitcher plant,Living stones or Lithops,Gordon,Rafflesia arnoldii,Andrea,Listen to the other students reactions to Mark,Gordon and Andreas descriptions of the plants.Write down the expressions they use.,Expressions of wonder:Thats amazing!What fantastic plants!Wow!How interesting!I think its fantastic!,Expressions of disgust:Oh,yuck!Thats disgusting!,UNUSUAL PLANT,TH:Today Mark,Gordon and Andrea are going to tell us about some unusual plants.Mark,do you want to go first?M:Sure.Today,I want to talk about an insect-eating plant called a pitcher plant.,Listening text,Heres a photo of it.Look at this part here.Its shaped like a pitcher.Its actually a leaf even though it looks like a flower.Its really clever-the insects are attracted by the sweet smell coming from what they think is a flower.But its a trap.,Once an insect goes down into the pitcher,it cant get out as there are small hard hairs pointing downwards that prevent it from escaping.In the end,the insect falls down into a pool of liquid at the bottom of the pitcher and gets digested by the plant.,S1:Thats amazing!S2:What fantastic plants!TH:Gordon.G:These are the plants Im going to talk about.Theyre often called“living stones”,but even though they do look a bit like stones,they are in fact plants.,S3:Wow!S4:How interesting!G:Their scientific name is Lithops and they come from South Africa and Nambia.The body of a lithops is actually a pair of leaves that have become rounded like a stone.This is because this plant lives in very,hot and dry places.When the leaves are shaped like this,not much water is lost from the plant.Another interesting thing about these strange plants is that theyre the same colour and appearance of the soil and stones around it.This makes them less obvious to animal looking for food.,TH:Thanks,Gordon.Andrea.A:Im going to tell you about Rafflesia arnoldii,a plant that has a flower about one metre wide.In fact,its the largest flower in the world.Rafflesia arnoldii doesnt have any leaves,stems or roots.It doesnt need them as its a parasite.It gets this food by,living on another plant.You might think that this flower should smell wonderful but it actually looks and smells like rotting meat!S2:Oh,yuck!S1:Thats disgusting!S3:I think its fantastic!,A:Me too.Anyway,it attracts insects that eat dead animals but instead of getting a feed,the insects pick up its pollen and spread it to other Rafflesias,Rafflesia arnoldii grows in the jungles in Indonesia but as the forests are being cut down,its becoming very rare.,TH:Thanks Andrea and thanks everyone.Those plants are certainly fascinating.,Listening on P75,Pre-listening,1.In which parts of the word would you find tropical rainforests?Tropical rainforests occur in three major regions:Asia,Africa and Central and South America.,2.Why do you think rainforests are being cut down?As populations increase,people need more land to live on.There are also mining companies which destroy forests in their search for minerals.,3.Why do you think tropical rainforests are important to the world?Because there are about 10 million species of plant and animal in the world.More than half of these live in the tropical rainforests.The rainforest could provide us with cures for diseases.,Also,rainforests absorb a lot of rain so that theres a constant supply of clean water running into rivers and lakes.,Number the topics below in the order in which you hear about them.,the area of the earths land covered by tropical rainforest reasons why rainforests are being destroyed the rate of rainforest destruction some consequences of rainforests being destroyed the best way to make money from rainforests,1,3,2,5,4,Are these statements true or false?Correct the false statements.,1.Rainforests cover 14%of the earths land surface.2.More than half of the rainforests have disappeared.,F,6%,T,3.150 acres of rainforest are destroyed every day.4.In 40 years time we might not have any rainforests left on earth.5.People can make more money from harvesting rainforest plants than from cutting down the rainforests.,F,Over 150 acres of rainforest are destroyed every minute.,T,T,THE DESTRUCTION OF TROPICAL RAINFORESTS Ed Walker(E)is interviewing Dr Anne Butler(A)about the destruction of tropical rainforests.,LISTENING TEXT,E:Anne,we hear a lot these days about how quickly tropical rainforests are disappearing.A:Yes,thats right.Rainforests now cover only 6%of the earths land surface.They used to cover about 14%,so more than half of the worlds tropical rainforests have,been destroyed,and thats in less than 50 years.Over 150 acres of rainforest is lost every minute in Asia,Africa,Central and South American.E:Thats unbelievable.,A:Yes,its frightening.The last remaining rainforests could be gone in less than 40 years.E:But why is this happening?A:Well,there are a number of reasons.As populations increase,people need more land to live on.Forests are cut down to plant crops or to start farms.,The wood is sold for firewood or building materials,furniture and paper,for example.And there are also mining companies which destroy the forests in their search for minerals.E:I suppose people have to make a living.,A:Yes,but you know,people can make more money by harvesting things like fruits,nuts and oils,as well as plants that can be used in medicine than by cutting down the forests.E:Oh really?I didnt know that.Now,could you outline some of the reasons why its not a good idea to destroy rainforests?,A:Sure.You must have heard about the rich animal and plant life in tropical rainforests.Well,there are about 10 million species of plants and animals in the world.More than half of these live in the tropical rainforests.So,destroying rainforests means that thousands of these species are dying out before weve even realized it.,E:Ive heard too that the rainforest could provide us with cures for diseases.A:Yes,there are certainly many new drugs waiting to be discovered.Another problem is that the destruction of forests contributes to global warming.,Also,rainforests absorb a lot of rain so that theres a constant supply of clean water running into rivers and lakes.If the trees are cut down,the rain isnt absorbed and there is flooding.,E:So,what can individuals do to help slow down the destruction?A:Thats a good question.Wade out),