人教版高二英语Reading 3.pptVIP

Unit 13 Properties of Water Warmer:Challenge Questions 1)Water is blue. 2)Water gets smaller when it freezes. 3)Rainwater is the purest form of water. 4)A glass of sea water is heavier than a glass of fresh water. 5)Water boils quicker at the top of a mountain than at the beach. 6)Hot water may freeze faster than cold water. 7)Water exists everywhere in three states. 8)The oceans never freeze because of the heat capacity of water. Task Two List the topic sentences of each paragraph: Para1:____________________make the ocean a great place to live. Para2:The _________________of water makes it an excellent medium for life. Para3:The _______ of sea water affects both its weight and freezing point. Outline Opening paragraph Opening para: 1)How long ago did life begin in the deep blue seas? 2)How many species are there in the oceans? 3)What makes the ocean such a good place to live? Task Three Reading Chemical Structure ◆ The water molecule is made up of two _______ atoms and one ________atom. ◇Water is _______. Salinity 1)What is salinity? 2)Why are the oceans salty? 3)What is it good for? What is density? Take a look at the two boxes below. Each box has the same volume. If each ball has the same mass, which box would weigh more? Why? Density 1) What is density? 2) How is it measured? 3) What is the density of water? 4) What is it good for? Heat capacity 1) What is heat capacity? 2) What do you know about the heat capacity of water from the text? 3)What it it good for? Ocean motion 1)What causes ocean motion? 2)What is it good for? Task4 True or false 1.The water molecule is made up of two hydrogen and oxygen atoms. 2.Water can break down everything except gases. 3.A kg of liquid water and a kilo of ice have the same volume. 4.A block of ice will float on liquid water. 5.If a substance has a density higher than 1000kg per cubic metre, it will sink in water. 6. Water is part of every living organism on the planet. 7.Oil floats on water because it