高二unit13reading课件.ppt

高二Unit13 Reading,万安中学 何志萍,The Properties of Water,What is water made up of ?,The molecule of water is made up of two hydrogen atoms and one oxygen atom.,What properties or characteristics do you know about water?,properties,What property of water does each of the four experiments illustrate? What causes this phenomenon? Whats this phenomenon related to?,Group work,The paper wont fall off. Because the air pressure can hold the paper and the water wont flow out.,The water and the oil wont mix. The oil floats on the water. It is because the densities of them are different. Water has larger density and mass.,The chalk will dissolve in the water. It is because water has the ability to dissolve the soluble (可溶解的) things and matters.,The ice cube floats on both salt water and fresh water, but ice dissolves faster in salt water. Because ice has smaller density and it can float on the fresh water and salt can help dissolve.,Pre-reading,Predict what the text is about by reading only the title of each paragraph. What are _? What do _look like?,the properties of water,the properties of water,What are different parts of _? What can _ be compared to? How do _ work? What are some examples of life _ _?,the oceans,the oceans,the oceans,in the ocean,True or fasle 1. Like all the other substances, water gets smaller when it freezes. 2. Pure water has a higher freezing point and lighter than salt water. 3. The salinity of the earths oceans is about 3.5%.,F,F,T,4. Other recourses such as oil, gas, gold etc is as precious as a drop of rain. 5. There are about five billion species in the oceans ranging from the tiniest plankton to giants like sharks and whales.,T,F,6. The water molecule is made of two hydrogen atoms and one oxygen atom. 7. Pure water has a higher freezing point and is lighter than salt water. 8. If a substance has a density 888kg/ m3, it will float on Water.,F,T,T,Multiple choices,1. Based on Para. I, the author tells us that there are various species in the oceans, indicating that _. Water plays a great role for marine life.,B. Ocean is a good place for life. C. There are many reasons for tiniest plankton and giants like sharks and whales. D. Ocean is part of the earth.,A,2. The water in the ocean is always moving in that _. A. The temperature of sea water is relatively high. B. Waters density affect changes in salinity and temperature.,C. Changes in salinity and temperature have effect on waters density. D. Waters in rivers always flow into the ocean.,C,3. Generally speaking, human beings are _ to large or suddenly changes in temperature. A. generous B. objective C. subjective D. sensitive,D,Answer the following questions,1. What is the importance of the chemical structure of water?,The chemical structure of water makes it an excellent medium for life and also makes it different from almost everything else on earth.,2. What is the salinity of the earths oceans?,The salinity of the earths oceans is about thirty-five parts per thousand, meanig that there are about 35 grammes of dissolved solids and gases in one kilogramme of water.,3. How about density and heat capacity?,Density is the relationship between mass and volume, measured in kilogrammes per cubic metre. Heat capacity is the amount of energy it takes to raise the temperature of a substance by one degree centigrade.,1. all the way e.g. Mrs Wang came all the way here. 王夫人径直到这儿来了。 2. makes it an excellent medium make + n.+n. e.g. I want to make my sister a pianist. 我想使我的妹妹成为一个钢琴家。,注意：可跟名词做宾补的英语动词并不多。常见的有：name；call；elect；choose等。 e.g. We chose him chairman of the important meeting.,3. make it different from make it + adj. e.g. You must make it clear that why you are late for school. 你必须讲清楚你迟到的原因,4. is made up of e.g. The water molecule is made up of two hydrogen atoms and one oxygen atom. 5. break down: 分解,分化 e.g. Chemicals in the body break our food down into useful substances. 人体中的化学元素把食物分解成有用的物质。,6. mix .with: 把和混起来 mix joy with sorrow 悲喜交集 7. affect: 影响; 使感染 e.g. Smoking affects health. 8. freezing: adj. 极冷的 frozen: adj. 已经结冰的 a freezing glance 冷淡的一瞥 be freezing cold 冰冻一样地冷,9. mass: quality (质量) the masses 群众, 民众 e.g. The masses have boundless creative power. a mass of 大量的 e.g. Before the rain, the sky was a mass of clouds.,10. is measured in measure v. e.g. Whether a girl is beautiful or not is measured by her soul. measure n. e.g. Kilogramme is the measure of weight.,11. absorb: take in e.g The ice absorbs heat and turns into water. absorb ones attention=draw ones attention be absorbed in 12. stable: balanced a stable relationship 稳定的关系 a stable man 一个稳重的人,13. sensitive: 对敏感 be sensitive to e.g. You should be sensitive to the change of the society. 14. steady: 平稳的; 稳固的; 稳定的 be steady in ones purpose 意志坚定的,e.g. If you are stead