人教版高中英语必修三Unit4 Astronomy：the science of the stars课件（29张PPT）

(共29张PPT)
Unit 4
Astronomy:
the science of the stars
How Life Began on the Earth
Reading
Step1:Fast reading
Skim the passage and complete the following exercises.
1.How does the author develop the passage
A.Give examples（举例）
B.In time order（以时间顺序）
C. Comparison（比较）
2.What’s the writing style of the text
A. Narrative 记叙文
B. Explanation 说明文
C. Essay 散文
How does the author develop the passage
Task 1:
Give examples（举例）
In time order（以时间顺序）
C. Comparison（比较）
What’s the writing style
of the text
A. Narrative 记叙文
B. Explanation 说明文
C. Essay 散文
Task 2:
1. A widely accepted theory was put up with.
What is it
2. What is the original earth’s atmosphere made up of
3. What is fundamental to the development of life
4. Which kind of life-being first appeared on the earth, plants or animals
5. Main idea of each paragraph
Step 2:Careful reading
Read the passage carefully to answer the following questions.
Paragraph 1:
1. A widely accepted theory was put up with. What is it
The universe began with
a “Big Bang” that threw matter in all directions. After that, atoms began to form and combine to create stars.
Paragraph 1:
Main idea:
A widely accepted theory about the formation of the universe.
Carbon dioxide, nitrogen, water vapour, and other gases
1. What is the original earth’s atmosphere made up of
Paragraph 2:
Main idea:
Paragraph 2:
The formation of the earth.
1. What is fundamental to the development of life
Water
Paragraph 3:
Main idea:
Paragraph 3:
The importance of water for life.
A cloud of dust
Combine into a solid ball
Explode…with fire & rock
(produce H2O, CO2,O2, N2, other gases)
atmosphere
Cool down
water appeared
dissolve harmful gases into …
Life began
Life developed
1. Which kind of life-being first appeared on the earth, plants or animals
At first, small plants began to appear on the surface of the water.
Paragraph 4:
Original cells appeared in the ocean.
The cells in the water began to separate. Marine animals came into being.
Some animals (amphibian & insects) came to land.
dinosaurs
Mammals
water
Plants in the water
Shellfish and fish
Insects and amphibians
Reptiles
Dinosaurs
Mammals
Plants on land
Paragraph 4:
Main idea:
Paragraph 4:
The development of plants and
animals on the earth
Man had evolved from apes.
Paragraph 5:
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.
1.
Main idea:
Paragraph 5:
The arrival of humans and
their impact on the earth
Main idea:
Summary
The text mainly tells us the formation
of the earth and the development of
life on it.
We have only one earth!
We should take care of the earth!
Homework
1. Read and learn good words, phrases or structures from Reading.
2.Find the noun clauses in reading.
Thank you!