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课件网) Lesson 25 Unit 5 Look into Science 掌握本课新单词: science, experiment, fill, prove, scientific, method. 掌握本课短语: do an experiment, fill…with, cover…with, turn…upside down, be (not) sure… 增强对科学实验的兴趣 学习目标 同学们，上一课学习的单词你们都掌握了吗？现在大家来检验一下，点击下面的音频开始听写吧！ Dictation Do you like doing experiments Why Lead in THINK ABOUT IT ·What kinds of experiments have you done in science class ·If you hold a jar that is filled with water upside down，what will happen Text presentation 新课讲授 Brian：Let’s do an experiment . I fill a jar with water. I cover the top with a piece of cardboard and hold it there. Then I turn the jar upside down and take my hand off the cardboard. Can you guess what will happen Danny：I think the floor will get wet. We should do this experiment outside，Brian. Jenny：I think the cardboard will hold the water. Danny：I don’t think so. Jenny：You think the water will pour out，Danny. I think the water will stay in the jar. Let’s test which theory is correct. Danny，Jenny and Brian are in the lab. Brian：Good idea，Jenny. That’s called the scientific method. Jenny：I am so sure of my theory that Brian can do the experiment over your head and I know you won’t get wet. Danny：Well，let’s try it! Brian：Are you ready，Danny Danny：No! Wait! (He puts on a raincoat and sits down.) Now I think I’m ready. Jenny：Brian，take your hand off the cardboard. Danny：No! (Danny closes his eyes tightly，and Brian takes his hand off the cardboard. The water stays in the jar.) Jenny：See，Danny! Danny：How is that possible Brian：The force of the air keeps the water in the jar. It is strong enough to hold the water. Danny：Wow! Brian：So what have we discovered ？ Jenny：We have discovered that the air pressure helps the cardboard hold the water in the jar. Brian：Right. What do you conclude，Danny Danny：I conclude that air is stronger than I thought. 11 10 1. Read the lesson and answer the questions. 1) Where does Danny think they should do the experiment 2) What keeps the water in the jar 3) Is Jenny sure of her theory？How do you know 4) Why does Danny put on his raincoat 5) What does Danny conclude Outside. The force of air. Yes, she is. She asks Brian to do the experiment over Danny’s head and she knows he won’t get wet. He is afraid that he will get wet. He concludes that air is stronger than he thought. Let's Do It ! 2. Read the experiment. Put the sentences in the correct order. □Put a piece of cardboard over the jar. □The jar of water is upside down，but the water stays in the jar. This is because air pressure pushes the cardboard onto the jar. □Fill the glass jar with water. □Turn the glass jar over quickly. Hold your hand on the cardboard for a few seconds. □Remove your hand from underneath the jar. What happens □There is more air outside the jar than inside，so there is more air pressure outside tha ... ...
