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nguyenanbadeu
2 năm trước
cho 3 đường thẳng x'x,y''y, z''z cắt nhau tại 1 điểm O. Trên Ox và trên Ox',theo thứ tự,ta lấy 2 điểm A và A' sao cho OA=OA'.trên Oy và trên Oy' theo thứ tự ta lấy 2 điểm B và B' sao cho OB =OB'.Trên Oz và Oz' theo thứ tự ta lấy 2 điểm C và C' sao cho OC=OC'. 1 chứng minh A'B=AB và A'B//AB. 2 chứng minh Tam giác A'B'C = tam giác ABC vẽ hình giúp mình luôn nha Hứa sẽ cho 5 sao và trl hay nhất
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VII . Read the passage and decide whether the statements are True or False There are three main kinds of pollution. Air pollution, and water pollution and noise pollution. Air , which is the most important element of our environment for our survival, can be polluted in many ways . Smoke in the air from mills, factories and industry contains carbon monoxide, carbon dioxide, and methane, which are all poisonous gases. This leads to health problems like asthma and lung diseases, and the thinning of the ozone layer, which protects us from harmful UV rays. China , the USA, Russia , India, Mexico and Japan are the world leaders in air pollution emissions. Water is also polluted by the discharge of commercial and industrial waste is into surface water. Sewage in drinking water is another cause of water pollution as it contains germs and viruses. The noise of vehicles, mills, and factories can be really unbearable. This kind of constant sound also causes headaches, tension, mental stress and migraines. People living next to a building site where there is too much noise can become sick, as they can not sleep or relax. This is called noise pollution 1. Air pollution, water pollution and soil pollution are main kinds of pollution. 2. Air plays the most important role in our survival. 3. Carbon monoxide, carbon dioxide and methane are poisonous gases. 4. The ozone layer helps to protect from harmful UV rays. 5. Chine, the USA, Russia , India, Mexico and Japan are the world leaders in air pollution prevention 6. The thinning of ozone layer is caused by smoke in the air from mills, factories and industry. 7. Sewage contains germs and viruses. 8. Noise pollution is caused by the discharge of commercial and industrial waste into lakes and rivers. 9. Noise pollution affects everybody’s mental health. 10. all people who live next to a building site become sick, as they can not sleep or relax

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