(
课件网) 3 The natural elements 10 Water Festival 1 ? Reading: Preparing for the Water Festival Who am I? I have no smell, no colour. Nothing can cut me. If you wash me more, I will be dirtier. Yeah! I am water! (True or false) Water is made up of hydrogen （氢）and oxygen （氧）. A. T B. F Water quiz 3) Water boils at 100 degrees Celsius. A. T B. F 2) H2O is the chemical formula（化学式） of water. A. T B. F 4) Ice sinks （下沉） in water. A. T B. F 7) How long could you live without water? A. About three months B. About seven days C. About one day 5) How much of your body is made up of water? A. 70% B. 25% C. 6% 6) How much water should you drink daily for good health? A. 1-2 glasses B. 3-4 glasses C. 6-8 glasses Think and answer 8) ____ of the surface of the Earth is covered with water. A. 75% B. 50% C. 10% 10)How much of the water on earth is available(可利用的）to drink? A. 95% B. 26% C. 1% 9) _____ of the water on the Earth is in the ocean. A. 30% B. 58% C. 97% Think and answer water ice steam 11) How many forms does water have? turn into [f??m] Look and say ? ? If we put the water into the fridge, 1 2 3 4 it fr_ _ zes and turns into ice. [fri?z] e e ? ? If we take out the ice from the fridge, it m _ lts and turns into water. e 1 2 3 4 [melt] ? ? When the water ____, it turns into _____. steam boils 1 2 3 4 ? ? When steam _____, it turns into water. cools down 1 2 3 4 lid [l?d] Listen and answer ? ? 1. What happens when water boils? 2. What happens when water freezes? 3. What happens when ice melts? 4. What happens when steam cools down? The three forms of water When..., it turns into... I’ve got some questions for you to think about. What happens when water boils? What happens when water freezes? What happens when ice melts? What happens when steam cools down? When water boils, it turns into steam. When water freezes, it turns into ice. When ice melts, it turns into water. When steam cools down, it turns into water. A. freeze B. melt C. cool down D. boil freeze melt boil cool down 冷却 ① ② ③ ④ Look and match: The three forms of water A: What happens when… ? B: When …, it turns into …. boils freezes melts cools down Pair work Group Competition: 1 2 5 6 4 3 What happens when water boils? When water boils ,it turns into steam. 1 ? ? Water. 2 ? ? Leave some ice cube in a bowl at room temperature. An hour later, what can you see in the bowl? Drops of water. 3 Put a dry lid on a glass of hot water. Wait for 10 seconds (秒).Take the lid off. What can you see under the lid? ? ? Drops of water. 4 ? ? Hold a plastic bag above a cup of hot water. After ten minutes, what can you see in the bag? Drops of water. The steam in the air turns into water on the cold glass. 5 Put some ice cubes in a glass of water. Wait for 2 minutes. Look at the outside of the glass. What is on the glass? How does it happen? ? ? What happens when steam cools down? When steam cools down, it turns into water. 6 ? ... ...
