1、Unit 4Astronomy:the science of the starsWarming upmedicinebiology chemistry astronomy physics mathematicsgeophysicsgeology physics biochemistrybiology chemistryAstronomy is the scientific study of the universeand the heaven bodies(such as the sun,the moon,and stars),gas,and dust within it.astronomer
2、Solar system1.Do you know how did the universe begin?Each religion or culture has its own ideas about the beginning of the universe?Pre-readingPangu separates the sky from the earth.Pangu separates the sky from the earth Pangu separated the earth and sky with an ax.After he died,his breath became wi
3、nd and cloud;his voice became thunder and his left eye sun and right one moon;arms and legs became edges and mountains;blood became rivers and tendon(筋脉)became roads;muscles became fields and hair stars;teeth and bones became metals,pearls and jade;sweat became rain.Reading How Life Began on the Ear
4、thDo you know the origin of the human beings?Man had evolved from apes.EarthHow life began on the earthThe Big BangwaterPlants in the waterShellfish and fishPlants on landInsects and amphibiansReptiles Dinosaurs Mammals watergreen plants on land234How life began on the earthAnalysing5678forestsshell
5、fish and all sorts of fishinsects(on land)amphibians(on land and in water)reptiles(on land)dinosaurs(on land)mammals(on land)small clever animals with hands and feet human small plants in water1A cloud of dustCombine into a solid ballExplodewith fire&rock(produce H2O,CO2,O2,N2,other gases)atmosphere
6、Cool downwater appeareddissolve harmful gases into Life beganLife developedThe development of lifeScanning1.What was produced when the earth exploded?2.How did water come into being on the earth?3.Where did life first begin,on the land or in the sea?4.Why were mammals different from other animals?1.
7、What was produced when the earth exploded?Water vapour,carbon dioxide,oxygen,nitrogen and other gases.2.How did water come into being on the earth?The explosion of the earth produced water vapor,which turned into water when the earth cooled down.3.Where did life first begin,on the land or in the sea
8、?In the sea.Because water dissolved harmful gases and made it possible for life to begin.4.Why were mammals different from other animals?Because they produced their young from within their bodies.Careful ReadingFinish the comprehending on page 27Think about what you have read and make choices.Why wa
9、s the earth different from other planets?A it produced a lot of heat.B.The water remained.C Water disappeared.D.It was the oldest planet.Why was life able to develop on the earth but not on other planets?A The earth had a solid shape.B.The earth did not have harmful gases in its atmosphere.C The wat
10、er stayed on the earth but not on other planets.D.The earth was not too hot and not too cold.Why was it necessary for plants to grow before animals?A Animals needed plants to protect them from the sun.B Plants provided oxygen for animals to breathe.C Animals could hide from hunters in forest.D It wa
11、s easier for plants to grow.What problem is caused by human being?A They exist everywhere on the earth.B They cause global warming.C They find new methods of growing crops.D They enjoy hunting and fishing.Text Retelling The explosion of the earth produced_ _,which turned into water when the earth co
12、oled down.Water allowed the earth to _ harmful gases into the oceans and seas.That made it possible for _ to begin to develop.The arrival of small _ encouraged the development of early _ and all sorts of fish.Many millions of years later the first green plants began to appear on land.watervapourdiss
13、olvelifeplantsshellfishLater land animals appeared.Some were_.Others,called_,were able to live on land as well as in the sea.When the plants grew into forests,_appeared for the first time.Then _developed,which became the most important animals on the earth for millions of years.After they disappeare
14、d,_ became more important.Text RetellinginsectsamphibiansreptilesdinosaursmammalsThey were the last group of animals and they were different because they _ their young from within their bodies.Small clever animals,with hands and feet,_ and _ all over the earth.As time went by,they covered the earth
15、and have become the most important animals on the planet.Text RetellingproducedappearedspreadLanguage points1.It exploded loudly with fire and rock,which were in time to produce the water vapour,1).（使某物）炸开，爆炸2).（指感情）激发3).（指人口）突然或迅速增加The firework exploded in his hand and he was hurt seriously.I was f
16、rightened when she exploded into loud laughter.Now it is not easy to find jobs with the exploding population.explosion n.爆炸（声）explosive adj.爆炸性的，易爆炸的n.炸药，爆炸物2.Nobody knew that it was going to be different from other planets going round the sun.be very/much/quite/entirely/totally different from与不同Cit
17、y life is quite different from country life.1）城市生活和农村生活很不同。2）他们的品位和我不同。Their tastes are different from mine.There are differences betweenand 与之间有不同之处tellfrom 把与区分开来the same as 与一样be similar to 与相似3.It allows the earth to dissolve harmful gases,whichallow vt.允许、许可、容许allow+n./pron./doing allow sb.to d
18、o be allowed to doMy father doesnt allow smoking at home.In fact he doesnt allow us to smoke anywhere at any time.父亲不允许在家里吸烟。实际上，他不允许我们在任何地方任何时候吸烟。Are we allowed to use the computer?我们可以用电脑么？4.This encouraged the development of early shellfish and all sorts of fish.encourage 鼓舞；促进；怂恿。后接名词、代词，也可接不定式作
19、宾语补足语。如：High prices for corn and wheat will encourage farming.玉米和小麦的高价将促进农业的发展。My success encouraged me to continue.我的成功鼓励我继续干下去。He encouraged me to learn dancing.他鼓励我去学跳舞。5.Many millions of years later the first green plants began to appear on land.lateadj.迟到的，晚的；前任的；以前的；已故的later adv.后来，较晚时候,过后 adj
20、.late的比较级(更迟的,更后的)latest adj.最新的lately adv.=recently 近来1)Mr.Zhu Rongji is the late Prime Minister of China.3)She said she would ring you later this morning.5)Its only lately that she has been well enough to go out.2)He is often late for school.4)Have you heard about the latest news?6.Small clever an
21、imals,now with hands and feet,appeared and spread all over the earth.vi.散布,传播，蔓延,伸展，扩展vt.铺开，摊开 1)The news spread through the school very quickly.2)Theres a desert spreading for hundreds of miles.3)He spread out his arms to welcome us.4)I spread a new cloth on the table.7.They are putting too much ca
22、rbon dioxide into the atmosphere,which prevents heat from escaping from the earth into space.阻止某人做某事:prevent sb.(from)doing sth.stop sb.(from)doing sth.keep sb.from doing sth.1)We must prevent them from making trouble.2)You should prevent the child from injuring himself.If nothing prevents,如果没有什么阻碍的
23、话,8.Whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.depend onsb./sth.sb.to do sth.sb.doing sth.sb./sth.for sth.相信，信赖,依靠,依赖,视而定，取决于1)When you are in a strange place youd better depend on the map.2)You cant depend on others to hel
24、p you.3)All living things depend on the sun for their growth.4)He depends on his pen for his living.wh-5)You can depend on him.Hell lead you there.6)Success depends on your own hard work.7)Our success depends on whether everyone works hard.depend on it 没问题，请放心（句末或句首）That/It(all)depends.那得看情况而定1)Depend on it,youll succeed.2)He may support me,but it depends.Tell him what you want to say;hes a man to _.A.count B.believe C.trust D.depend 解析:相信/信赖某人:count on sb.believe in sb.depend on sb.trust(in)sb.C
