高二英语Astronomy教案

Show the questions on the screen.

1. What was there on the earth before life could begin?

2. Why do scientists think there has never been life on the moon?

3. Why did animals first appear in the seas?

4. Why did green plants help life to develop?

5. Why were mammals different from other animals?

T: Now who can answer the first one?

S1: Water vapour, carbon dioxide, oxygen, nitrogen and other gases.

T: What about the second one?

S2: Because there is no water on the moon.

T: What about the third one?

S3: Because water allowed the earth to dissolve harmful gases into the oceans and seas.

T: The fourth one?

S4: Because green plants can take carbon dioxide from the atmosphere and fill the air with oxygen.

T: What about the last one?

S5: They were different because they produced their young from within their bodies.

T: Well done! Now turn to Page 26 Comprehending1, I think you may continue to read it again to get more details.

Skimming

In this part, Ss will read the text again and then finish Part1, 2 and 3.

T: Now please skim the passage fast to finish Part1. Then we will check the answer.

Key to Part1: BCBB

T: Skim Paragraph 2, 3 and 4, and finish Part 2 and 3.

Key: DBIGEHACFJ

T: For Part 3, discuss them with your partner.

T: Why is it wrong in films and stories to show dinosaurs and people together?

S: Because dinosaurs died out long before human beings developed on the earth.

T: Do you agree with him?

S: Yes.

T: What about the answer to the second question?

S: They are the cleverest animals because they have larger brains than any other creatures on the earth so far.

T: Excellent job! I’ll check how much you have learned about the passage.

Step V Listening

Listen to the tape for the students to follow and have further understanding of the passage.

T: Read after the tape, then answer me some questions with your book closed.

Play the tape

T: How did water come into being on the earth?

If one student can’t answer completely, ask two or three or more students.

Ss: The explosion of the earth produced water vapor, which turned into water when the earth cooled down.

T: Why is water important on the earth?

Ss: Because water allowed the earth to dissolve harmful gases into the oceans and seas.

T: No.3, finish the following form.

Key to the exercise:

2. shellfish and all sorts of fish 5.amphibian(on land and in water)

7. reptiles (on land) 8.dinosaurs(on land) 9.mammals(on land)

T: That’s all for this passage. Now let’s deal with some language points.

Explanation

T: Turn to Page 25. Let’s look at the sentences:

1. It exploded loudly with fire and rock, which were in time to produce the water vapour.

which leads non-restrictive attributive clause.

in time: sooner or later; eventually

I’ll see him in time.

in time (for sth. /to do sth.): not late

She will be back in time to prepare dinner.

in / out of time: in/not in the correct time

The audience clapped in time to the music.

2. Nobody knew that it was going to be different from other planets going around the sun.

be different from: not like someone or something else in one or more ways

Note: We can use very, much, quite, entirely, totally to modify different

City life is quite different from country life.

going around the sun is-ing form that serves as attributive.

Men breaking the law will be punished.

Can you see the girl dancing with your boyfriend?

3. Whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.

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