人教版高中英語(yǔ)必修三第四單元How Life Began On The Earth課件

The origin of life on the earth.Pre-reading Nearly everybody has this or that puzzles:How do human beings come into being?How does the earth come into being?Do you know any ancient idea about the beginning of the universe?Big BangHow many parts can this text be divided into?In what order is this text written?uThis passage can be divided into two parts:Part 1(para1-3):The development of earth.Part 2(para4-5):The development of life.life in the water life on the landuOrder of writing:timeScanning uRead this passage quickly and match the right main idea of each paragraph.uFill in the blanks to get its main idea.Para.1 Para.2Para.3Para.4Para.5 A theory about how the universe was formedThe formation(形成）形成）of the earthThe importance of water for lifeThe development of plants and animalsThe arrival of humans and their effects on the earthPart1:The development of the earthPart2:The development of life.How Life Began On The EarthMain idea:The text mainly tells us the formation(form)of the earth and the development(develop)of life on it.While-readingWhile-readingPart 1:The development of the earthPart 1:The development of the earthPart 1:The development of the earth1.After the Big Bang,what was the earth like?a cloud of dust a solid globe 2.What made up(構(gòu)成構(gòu)成)the earths atmosphere after the earth exploded?Carbon dioxide,nitrogen,water vapour and other gases.3.Why is water so important for the beginning of life?Because water allowed the earth to dissolve harmful gases and acids into oceans and seas.sion produce?A cloud of dustA cloud of dustsettle into a settle into a solidsolid globe globeExplodeExplodewith fire&rockwith fire&rock(produce C,N(produce C,N2 2,H,H2 2O,and other gases)O,and other gases)madeatmosphereatmospherewater appearedwater appeared Cool downCool downHow did the earth come into being(產(chǎn)生）產(chǎn)生）?the e the edissolve harmful gases into dissolve harmful gases into Part 2:The development of lifePart 2:The development of lifewater 1.2.10.3.4.insects(on land)5.6.7._8.dinosaurs(on land)9._ small _ in water_ and all sorts of fishgreen plants on land _(on land and in water)forests (on land)(on land)small clever animals with _plantsshellfishamphibiansreptilesmammalshands and feetA timeline of the development of lifeWhat are the small clever animals?Are they taking care of the earth very well?What problem are humans causing?Because they are putting too much carbon dioxide into the atmosphere,which prevents heat from escaping from the earth into space.The earth may become too hot to live on.Linkin Park What Ive doneWhat will happen when we put too What will happen when we put too much CO2 into the atmosphere?much CO2 into the atmosphere?greenhouse effect greenhouse effectglobal warmingglobal warminganimals will die outanimals will die outplants will die outplants will die outThere will be no life on the earthThere will be no life on the earthDiscussionDiscussionrise of the sea levelrise of the sea levelicebergs and glaciers melticebergs and glaciers meltAs a student,what little things can we do for the earth?Suggested Answers:control the populationPlant more treesStop litteringDevelop clean energyGo to work by bus rather than by carrecycle rubbishsave waterand so onGame Lets play a game.Suppose you are an astronomer and you are asked to deliver a speech about the development of life one the earth.You can refer to the chart bellow and begin like this:Good afternoon,I am Dr.Im greatly honored to be here to give you a speech about the development of life Good morning/afternoon,I am Dr.Im greatly honored to be here to give you a speech about the development of liHow life began on the earth“Big Bang”a cloud of dustSummary a solid globethe earths atmosphereOthergassesWater:fundamental to the development of lifewater vapour nitrogen carbonextremely small plands on the surface of the waterearly shellfish and all sorts of fishgreen plants on landland animalsinsectsamphibiansreptileshuge animals(dinosaurs)the rise of mammalshuman beings Fill in the blanks according to the text.The earth was just a cloud of dust after the“Big Bang”.The earth exploded(explode)loudly with fire and rock.They were in time to produce many things,which were to make the earths atmosphere.As the earth cooled down,water began to appear on its surface.It allowed the earth to dissolve harmful(harm)gases.Then life began to develop.The first small plants multiplied and filled the oceans and seas with oxygen.This encouraged the development(develop)of early shellfish and fish.Land animals such as insects,reptiles,dinosaurs and so on appeared after green plants appeared.Small clever animals spread all over the earth.They are putting too much carbon dioxide into the atmosphere,which prevents heat from escaping(escape)from the earth into space.Whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.Homework Try to retell this passage according to the chart on your paper.Write a composition(作文)about how to protect the environment.