人教高中英语必修3Unit4Astronomy: the science of the stars reading（共23张PPT）

(共23张PPT)
Unit 4
Astronomy: the science of the stars
How Life Began on the Earth
Period 1
Is there life on these planets?
religious ideas/legends: China
western countries
scientific theories:
How did life begin on the earth?
Pre-reading
Pangu(盘古) separated the sky from the earth.
Nvwa(女娲) made human beings.
God created the world and all living things.
The Big Bang

Which do you believe, the religious legends or the scientific theory?
Fast reading: main idea
Para.1
Para. 2
Para. 3
Para. 4
Para. 5
The importance of water for life
The arrival of humans and their influence on the earth.
The formation(形成) of the earth
A widely accepted theory of the origin of the universe.
The development of plants and animals on the earth.


Analyze the structure of the text
Introduction
Body
Para.1
Para. 2
Para. 3
Para. 4
Para. 5
theory________
the formation of the_____________
the development of _______________________
earth and its water
living things and their influence
Big Bang
Big Bang
A cloud of dust
Settled into ______________
Exploded …with ____________
(produced__________________________)
atmosphere
Cooled down
water appeared
Life began
Careful reading: para2 origin of the earth
a solid globe
fire & rock
CO2, N2, H2O,other gases
Para 3: importance of water
Questions:
1.Why there is no life on other planets like Mars?

2.What is the significance(重要性)
of the continued presence
of water on the earth?
1.__________ in water
2.__________________
6. forests
4._________
5._________
3.__________on land
7._________
8._________
9._________
→
→
→
insects
amphibians
reptiles
dinosaurs
mammals
plants
animals
shellfish & other fish
small plants
green plants
Para 4: development of life
O2
Life is developing all the time.
Para 5: human beings
Questions:
1.What appeared later? What do they look like?

2. What problems do they cause?
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 .
Can you put the development of life according to time order?
1. Insects and amphibians appeared.
3. The earth became a solid globe.
5. Reptiles appeared.
7. The earth was a cloud of dust
9. Shellfish and other fish appeared.
11. Clever animals with hands and feet appeared
2. Dinosaurs appeared.

4.Small plants grew on the surface of the water.
6. Plants began to grow on dry land.
8. Water appeared on the earth
10. The universe began with a “Big Band”.
12. Mammals appearedred.
8
3
9
2
6
12
10
5
7
4
1
11
Ex.2 on P27
Thinking and discussion:

As students, what can we do to slow down the speed of global warming?
We can ride bikes.
We can plant more trees and try to protect them.
We can turn off lights when we do not use them.
We don't need to do big things—we can start out small.
From today on!
Homework
1. Finish the exercise on section A2 of your English paper.

2. Review the key words and useful expressions in the lesson.