人教版高二英语The Properties of Water.pptVIP

The Properties of Water Life on earth began in the oceans about three billion years ago; 99% of the living space on earth is in the oceans; There are about five million (known) species in the oceans; Life in the oceans ranges from tiny plankton to giant whales. * * * * * Questions related to the subjects What is/ are _____________________? What does _____________________ look like? What are different parts of __________? What can ___________ be compared to? How does ___________ work? What are some examples of ______________? the properties of water (one property of water) the oceans the oceans the oceans life in the ocean Structure of the passage 1 minute to skim the passage, focusing on the titles (title and subtitles)in the text and then fill in the chart below. You do not need to read the whole text. CHEMICAL STRUCTURE SALINITY THE PROPERTIES OF WATER DENSITY HEAT CAPACITY OCEAN MOTION Find out some basic facts about life in the oceans Basic facts about life in the oceans from the opening paragraph : True(T) or false (F) 1.Life on the earth began on the land some three billion years ago. 2. Life in the ocean ranges from tiny plankton to giant whales. 3. The water molecule is made up of two oxygen atoms and one hydrogen atoms. 4. Because water is polar,it can not break down nutrients quickly. 5. Water is solid at room temperature. 6. Sea water is similar to pure water in many ways,but is heavier and has a higher freezing point. 7.A substance with higher density will float on a substance with lower density. 8.Because the density increases when the water freezes,the ocean never freezes. 9. The heat capacity makes the ocean a safe and comfortable habitat to live in. Water is a liquid at room temperature, and it has a relatively high freezing point. The reason why water can dissolve most substances on earth is that water has high heat capacity. Like all the other substances, water gets smaller (contract 缩小) when it freezes.