T: Very good! Can you put them in right order?

S7: Amphibians, Reptiles, Dinosaurs, Mammals, Beijing Ren.

T: Do you know what it was like before life appeared on earth?

S8: It was full of water, perhaps.

T: Before that, what was it like?

S9: Sorry, I don't know.

T: Do you want to get more information? Today we'll learn something about How Life Began on the Earth. Turn to Page 25. Let's come to Warming up first.

Step 2. Warming up

1. Read the three questions, while the students listen and follow.

2. Give the Ss several minutes to discuss the questions.

3. Collect answers from the whole class.

4. Check the answers while discussing.

T: I'll read the three questions for you. You should listen to me carefully. (If students don't know how to discuss, show them an example.) For example, medicine. When someone gets serious illness, he will go to the hospital. The doctor will examine him. He will take his temperature, measure his blood pressure and give him an X-ray, or a CT. For the whole process of the examination, what kind of science has been used?

S1: Biology.

S2: Chemistry.

T: So we can say medicine combines biology and chemistry. What about biochemistry and geophysics?

S3: I think biochemistry combines biology and chemistry.

S4: Geophysics combines geology and physics.

T: What about astronomy?

S5: Physics.

S6: Mathematics.

T: Very good. We should know that astronomy is a multidisciplinary subject and if we want to do some research on it, we should know many science subjects related to it. Now discuss the second question: