Unit4 Astronomy Reading学案

Unit4 Astonomy: the science of the stars
How Life Began On the Earth学案
Aims: 1. After reading, students be able to know some astronomic knowledet;
2. Students can grasp the main idea and the structure of the passage;
3. Improve students’ reading ability.
Part One:
Scanning:
Read the passage quickly and answer the questions.
1. When did the “Big Bang” happen?
2. What form was the earth after the “Big Bang”?
3. What made up the earth’s atmosphere
4. How did water come into being on the earth?
5. What’s the significance of the presence of water on the earth?
6.What was important to the development of fish?
7. What made possible the rise of mammals on the earth?
8. Why are mammals different from all life forms in the past?
Detail reading
I. Read the passage carefully and match the main idea with each paragraph. Para. 1 The formation (形成) of the earth.
Para. 2 The importance of water for life.
Para. 3 A widely accepted theory about the formation of the universe. Para. 4 The arrival of humans and their impact on the earth.
Para. 5 The development of plants and animals on the earth.Ⅱ.Finish the Exercise 2 on the book according to the questions above. III. Fill in the blanks in the following form.
IV. True (T) or False (F).
1. The earth appeared before the Big Bang happened.
2. The original atmosphere consisted of nitrogen and oxygen.
3. The main difference between the earth and other planets is that there is water on the earth.
4. Life began in water and then on land.
5. Mammals appeared before the development of dinosaurs.
6. Dinosaurs could give birth to young baby animals and produced milk to feed them.
7. Human beings produce too much carbon dioxide which causes the global warming on the earth.
8. According to the text, human beings would disappear in the end.
Post reading:
Speaking: What should we do for our earth?
Part two:
Phrases and Useful Expressions
1. 及时；终于___________________
2. 产生；分娩_______________
3. 轮到某人_____________________
4. 阻止；制止_________________
5.挡住（光线）__________________
6. 感到高兴____________________
7. 既然__________________ 8. 突发；爆发_________________
9. 密切注视_______________ 10. 下蛋____________________
11.依赖，取决于_____________ 12向前迈步_________________
13.和…..一样痛苦_____________ 14.爆发_____________
15.be different from___________ 16. go round…___________
17fill…with…_______________ 18.as well as _______________
19escape from_______________ 20.as…as possible _______________
21 make a trip _______________ 22.fall to the ground _______________ 23.fall back _______________ 24.get close to _______________
Part two. Reading materials
长句难句:把下列句子翻译成汉语。

1.What it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust settled
into a solid globe.
_____________________________________________________________________________________ 2. What is even more important is that as the earth cooled down, water began to appear on its surface.
_____________________________________________________________________
3.What many scientist believe is that the continued presence of water allowed the earth to dissolve harmful gases and acids into the oceans and seas.
_____________________________________________________________________
4.Why they suddenly disappeared still remains a mystery.
_____________________________________________________________________
5.So whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.
_____________________________________________________________________
6.This produced a chain reaction, which made it possible for life to develop.。