This lesson is mainly a reading skills training class. How life began on the earth, is the passage from Student's Book 3 Unit 4 , is concerned with astronomy and how human beings first evolved on the earth and understand the universe around them.

　　1. Talk about and understand the beginning of life on the earth.

　　2. Discuss the order of development of life.

　　Step 1 Lead in

　　Talk about science subjects

　　T: Good morning/afternoon, everyone. What class do you have today?

　　S1: Maths, English, Chinese, physics, history, and geology.

　　T: What other subjects do you have in school?

　　S2: Computer, chemistry, biology, music, PE, and politics.

　　T: Which is your favourite? Why?

　　S3: My favourite one is ...because it's very interesting/exciting/instructive/...

　　S4: I like ...best because ...

　　T: Which ones are science subjects?

　　S5: Physics, chemistry, biology, geology and mathematics.

　　T: All these subjects play an important role in the study of science. What subjects are used to study medicine? How about biochemistry? What about geophysics? What subjects are part of astronomy?

　　S6：Mathematics and physics.

　　T: Can you understand the following combined science subjects?

　　→physics + mathematics = astronomy

　　→geology + physics = geophysics（地球物理学）

T: What does astronomy deal with?