课件36张PPT。Unit 4 Astronomy：the science of the stars
Warming Up & Reading (Ⅰ) 1. Try to talk about the science of the stars.
2. Talk about the beginning of life on the earth.
3. Discuss the order of development of life.
4. Understand the details about the passage.Learning aims地球 ______
木星 ______
火星 ______
水星 ________
海王星 _________
F. 土星 ________
G. 天王星 _______
H. 金星 ________EarthJupiterMarsMercuryNeptuneSaturnUranusVenus1. Can you name each planet correctly using the letters given in the blanks below? Leading-in
The Big Bang
watersmall plantsinsects and amphibians
on landreptiles on landmammalsdinosaurs2. How did life begin on the earth?
The Big Bang advanced mammalsthe beginning of the lifePangu separated Nvwa created God created
created the sky humans the world
《盘古开天》 《女娲造人》 《上帝创世论》3. Do you believe the passage which tells you the truth about the beginning of life? Why? 1. Read the passage quickly to find the main idea
of the text.
The text mainly tells us the _________ of the earth and the ___________ of life on it.
formationdevelopmentSkimmingReading
How Life Began on the Earth2. Conclude the main idea of each paragraph.
1) A widely accepted ______ about the _____ of the universe.
2) The formation of the ______.
3) The __________ of water for life.
4) The development of ______ and _______ on the earth.
5) The arrival of _______ and their ______________ on the earth.theoryoriginearthimportanceplantsanimalshumansinfluence/ effect1.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?Listening and ScanningAnswer the following questions：1. What was produced when the earth exploded?
Carbon, nitrogen, water vapour and other gases.
2. How did water come into being on the earth?
The explosion of the earth produced water vapour, which turned into water when the earth cooled down.3. Where did life first begin, on the land or in the sea?
In the sea. Because water dissolved harmful gases and made it possible for life to develop.
4. Why were mammals different from other animals?
Because they gave birth to young baby animals and produced milk to feed them.Detailed Reading
1. This text can be mainly divided into two stages:
Stage 1 : The development of the earth
Stage 2 : The development of life
(Paras. 1～3)(Paras. 4～5)Stage 1: The development of the earth(1) After the Big Bang, what was the earth like? a cloud of dust a solid globe exploded loudly with fire and rock produced water
vapour and gases(2) What happened next?(3) What did the water vapour and gases form?the earth’s atmospherewater appeared(4) What appeared as the earth cooled down?Water is important for the beginning of life on the earth. Stage 2: The development of life Small plants appeared on the surface of the water.(1) What life developed after water appeared?Shellfish and all sorts of fishes. (2) What life developed in water next?Green plants began to grow on land. Insects appeared.(3) What about the life on land?Amphibians on land as well as in the water.forests(4) What life developed next on land? Reptiles appeared. Dinosaurs developed. (5) What life developed after forests appeared?Mammals on land.(6) What life developed after dinosaurs?Small clever animals.(7) What life developed after mammals?(1) (2)(3)(4)
(5)(6)(7)
(8)
(9)
(10)small plants in watershellfish and
all sorts of fish insects reptilesamphibiansmammalsdinosaurs humansplantsanimals green plants on landforests2. Can you fill in the blanks?8391262Insects and amphibians appeared.
The earth became a solid ball.
Reptiles appeared.
The earth was a cloud of dust.
Shellfish and other fish appeared.
Clever animals with hands and feet appeared.3. Can you put the order of development of life into a timeline?Ex.2 on P2710115174Dinosaurs appeared.
Small plants grew on the water.
Plants began to grow on dry land.
Water appeared on the earth.
The universe began with a “Big Bang”.
Mammals appeared. Choose the best answers.1. Why was the earth different from the other planets?
It produced a lot of heat.
The water remained.
C. Water disappeared.
D. It was the oldest planet.Further Reading 2. Why was life able to develop on the earth but not on the other planets?
A. The earth had a solid shape.
B. The earth did not have harmful gases in its atmosphere.
C. The water stayed on the earth but not on the other planets.
D. The earth was neither too hot nor too cold.3. Why was it necessary for plants to grow before animals?A. Animals needed plants to protect themselves from the sun.
B. Plants provided oxygen for animals to breathe.
C. Animals could hide from hunters in the forest.
D. It was easier for plants to grow.4. What problem is caused by human beings?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. The explosion of the earth produced _____ _______, which turned into water when the earth cooled 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. watervapourRetelldissolvelifeplantsshellfishClass exercises Later land animals appeared. Some were ________. Others, called ___________, were able to live on land as well as in the water. 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 disappeared, _________ became more important. insectsamphibiansreptilesdinosaursmammals They 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 and have become the most important animals on the planet.producedappearedspreadHomework
1. Finish the exercises 1 and 2 on Page 63.
2. Read the text again and find out your difficult points.Look before you leap.
三思而后行。
