1、Unit 4,Section ,Step 1,Step 2,Step 3,Step 4,Step 5,1With the development of science and technology, China has sent up Tiangong1 successfully and is working on building a space station.Are you interested in space station?2Why do the sixteen countries spend a lot of money building the International Sp
2、ace Station?,The International Space Station (ISS) will be a little “city in space” orbiting (沿轨道运转) 250 miles above the earth.About the size of two football fields, the space station will be a place where people from around the world can live and study in space over long periods of time.The ISS is
3、an extremely expensive project, but it will someday serve as a steppingstone for future space exploration.,Sixteen countries from around the world are working together on the International Space Station.These international partners are the United States, Russia, Canada, Japan, Brazil and Euro,pean S
4、pace Agency (Belgium, Britain, Denmark, France, Germany, Italy, the Netherlands, Norway, Spain, Sweden, and Switzerland) .,Risking the dangers of space, the sixteen countries are spending billions of dollars and many years building the space station because they believe they can benefit a lot from i
5、t.Perhaps the most important benefit is that the space station allows humans to live and study for long periods in microgravity (微重力)，or a “weightless” environment.,Think of the space station as a steppingstone to the starts.If humans are ever going to travel to other planets, such as Mars, we must
6、understand the effects of such long journeys on the human body.Weve learned from past space travel that living in microgravity leads to the weakening of bones and muscles.The space station will allow scientists to understand these effects and study possible solutions for longterm space travel.,But s
7、tudying in microgravity is not the only reason for the space station.For the first time, we will be able to observe the earth from different angles (角度) over long periods of time.The space station will allow us to watch changes in the environment to better understand our own planet.The space station
8、 will also give us an opportunity to study the environment of space.,1Do you know how many planets circle around the sun in our solar system？What are they?,_参考答案：Venus(金星)；Earth(地球)；Mars(火星)；Mercury (水星)；Jupiter (木星)；Saturn (土星)；Uranus(天王星)；Neptune (海王星),2.Each religion and culture has its own ideas
9、 about how life began on earth.What do you know?,_参考答案：In China, we all know that Pangu separates the sky from the earth.In western culture, God created the world in six days.Many scientists believe that the universe began with a huge explosion called the Big Bang.,Scan the passage and then choose t
10、he best answers according to the passage.1What began to appear on the earths surface when it cooled down?AWater.BGases.CAcids. DCarbon.2From the last paragraph we can infer that the author is _.Aconfident BsadCconcerned Dangry,3What does the word “they” refer to in the sentences “It exploded loudly
11、with fire and rock.They were in time to produce carbon, nitrogen, water vapour and .”？APlanets. BStars.CGases. DFire and rock.4Which is the right order of the development of life?ASmall clever animalsshellfishdinosaursmammals.BShellfishdinosaurssmall clever animalsmammals.CShellfishdinosaursmammalss
12、mall clever animals.DDinosaursshellfishmammalssmall clever animals.,5Why were mammals different from other life forms?ABecause they gave birth to young baby animals and produced milk to feed them.BBecause they produced young generally by laying eggs.CBecause they were able to live on land as well as
13、 in the water.DBecause they live on grass.答案：15ACDCA,1Read the passage and write down the main idea of it.The text mainly tells us the _of the earth and the_of life on it.答案：formation; development,2Put the order of development of life into a timeline.(1)_AInsects and amphibians appeared.(2)_ BDinosa
14、urs appeared.(3)_ CThe earth became a solid ball.(4)_ DSmall plants grew on the water.(5)_ EReptiles appeared.(6)_ FPlants began to grow on land.(7)_ GThe earth was a cloud of dust.,(8)_ HWater appeared on the earth.(9)_ IShellfish and other fish appeared.(10)_ JThe universe began with a “Big Bang”(
15、11)_ KClever animals with hands and feet appeared.(12)_ LMammals appeared.答案：(1)(5)JGCHD(6)(10)IFAEB(11)(12)LK,3Read the passage and match each paragraph with its main idea.Paragraph 1 _AHow humans appeared and what effects they have caused to the earth.Paragraph 2 _ BWater is very important for lif
16、e on the earth.Paragraph 3 _ CHow the earth formed.,Paragraph 4 _ DHow the plants and animals on the earth developed.Paragraph 5 _ EIt is widely accepted that the universe began with a “Big Bang”答案：15ECBDA,Read the passage carefully and fill in the blanks. The earth was just a cloud of 1._after the
17、“Big Bang”The earth 2._loudly with fire and rock.They were in 3._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 4._gases.Then life began to develop.,The first small plants 5._and filled t
18、he oceans and seas with oxygen.This encouraged the 6._of early shellfish and fish.Land animals such as insects，reptiles and dinosaurs and so on appeared after green plants appeared.Small clever animals 7._all over the earth.They are putting too 8._carbon dioxide into the atmosphere, which 9._heat fr
19、om the earth into space.Whether life will continue on the earth for millions of years to come will 10._on whether this problem can be solved.,答案：1.dust2.exploded3.time4.harmful5multiplied6.development7.spread8.much9prevents10.depend,1What problems have been caused by humans to the earth?,_答案：The earth is becoming warmer and warmer.,2As a student, what little things can we do for the earth?_答案：(1)We should make full use of solar energy; plant trees; recycle rubbish; save water and so on.(2)Only if we care will we help; only if we help shall all be saved!,
