Unit 3单元重点及考点精讲专练课件2022-2023学年沪教牛津版九年级英语下册

单 元 习 复 9 B Unit 3 单元重点及考点精讲专练 课文跟读 考点导航 课文复述 考点专练 考点归纳 单元重点词汇过关 1 2 3 4 5 6 Content The world is in danger Our world is in danger. We must do something to protect the environment. But, what are the main problems we face? The greenhouse effect The atmosphere around the Earth is necessary for all living things. It is like the glass of a greenhouse, letting sunlight in and keeping heat from getting out. Without it, the Earth would be the same as the Moon—cold and lifeless. When we burn fuels such as petrol and coal, we produce a gas called carbon dioxide (CO2). Too much of this gas pollutes the atmosphere, and causes it to keep in too much heat. As a result of the greenhouse effect, the Earth’s temperature is increasing. This causes sea level to rise, and in the future may cause cities to disappear. Cutting down forests Every year, we destroy nature by cutting down huge areas of forests. This makes the greenhouse effect worse because trees take in CO2 and produce oxygen. Cutting down trees also destroys the homes of the animals that live in our forests, and causes the surface of the soil to be easily destroyed by rain. This can result in floods and even more damage to the environment. 课文 1 考点导航： the same as, like和be different from的用法区别。这一考点在考试中主要在两种题型中考查，即“语法选择”和“完成句子”。 课文跟读 3 Bad habits Many of our habits cause pollution. People often use things once and then throw them away, or leave them on the ground as litter. This creates mountains of rubbish and pollutes our land and seas. In order to protect the environment, we need to take proper action. We should be different from many consumers and become “green consumers”. This means that we should only buy and use products friendly to the environment. We should also recycle as many things as we can. We can reuse things for the same purpose as before, or we can use them for new purposes. If we just learn to live in new and different ways, we can make a difference. different from ◎9B