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cho 1g sắt clorua chưa rõ hóa trị của fe vào dd AgNo3 dư, ng ta thu đc 2.65 g 1 chất kết tủa trắng. xác định công thức của muối sắt clorua . Mng giúp mk với ạ
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III. Complete the sentences, using the correct form of the words in brackets. 1. habitats have been destroyed in recent years. (nature) 2. A number of cleaning products contain chemicals. (harm) 3. Water samples collected at these villages were seriously with bacteria. (contaminate) 4. People believe that the water has brought cancer to the local residents. (pollution) 5. Light pollution make us to see the stars in the sky. (able) 6. Noise is considered as pollution. (environment) IV. Complete the sentences, using the correct form of the words in brackets. 1. The soil becomes because of the use of so many pesticides and fertilizers. (contaminate) 2. waste spills can contaminate groundwater.(industry) 3. In many developing countries, water pollution is usually a leading cause of . (die) 4. elements have been found in both ground and underground water sources.(pollute) 5. Fish and many other animals are killed by in their habitat.(pollute) 6. Astronomers are concerned about light pollution because they have in viewing activities in the sky and outer space. (difficult) V. Combine each pair of sentences, using conditional sentences type 1. 1. A person looks at the sky at night. He is not able to see the Milky Way by naked eye. 2. Noise pollution happen regularly. It causes stressor nuisance. 3. Water pollution gets more serious in the future. It affects the development of economy the pollution and society. 4. Australia has invested in water in Viet Nam with good results. Haft of the population in the rural areas has access to fresh water. 5. You use compact light bulbs. You save a lot of energy. 6. We have more space. We plant more trees. VI. Choose the word or phrase among A, B, C or D that best fits the blank space in the following passage. Light pollution is not (1) serious as water or air pollution. (2) , it is the type of pollution that (3) more in cities than in rural area. In the past, we could sit out at night and (4) at glittering stars in the sky and light from objects in the outer space. Nowadays, cities are covered with lights from buildings,streets, advertising displays, many of which direct the lights up into the sky and into many unwanted places. The real problem is that it is very (5) to apply light to almost everything at night. Millions of tons of oil and coal (6) to produce the power to light the sky. Eye strain, (7) of vision and stress are what people may get from light pollution. (8) light at night can harm our eyes and also harm hormones that help us to see things properly. 1. A. more B. as C. much D. only 2. A.Moreover B. However C. Therefore D. Nevertheless 3. A. happen B. occur C. occurs D. is occurred 4. A.watch B. see C. spend D. spend 5. A. waste B. wastes C. wasting D. wasteful 6. A. used B. using C. is used D. are used 7. A. lose B. lost C. loss D. losing 8. A. Very much B. Too much C.Too many D.So many

XII. Read the passage, and choose the correct answer A, B, C or D for each question. Saving the Environment: One Home at a Time Pollution can be seen not only throughout the world, but also in our own homes. It comes from household chemicals, the amount of water people use and the waste people produce and throw away. What can be done to stop this pollution? Surprisingly, a person can help save the environment by doing simple things. First, we need to recycle, which allows products to be used over and over again. Recycling can also reduce the number of trees cut down to produce paper products. It takes very little effort. It is not hard to place plastic and glass bottles, aluminum cans and paper in a bin. Anyone can do it. Second, we need to watch the amount of water used at home. It can be conserved by taking short showers instead of baths, repairing leaky faucets, using the dishwasher or washing machine only when fully loaded, or simply turning the faucet off while brushing your teeth. Third, we need to reduce waste. We need to recycle whenever possible, but should also try to use this waste effectively. For example, grass clippings and food scraps can be made into compost for plants. The average person produces 4.3 pounds of waste every day, but we can reduce that amount by recycling and reusing. If we do our part in our own homes, we can help keep the planet from becoming more polluted. 1. Pollution is caused from the following sources except . A. water in rivers B. water from households C. wastes D. house chemicals 2. Recycling can help us . A. never cut down trees B. produce more paper products C. place garbage bins easily D. use products again and again 3. In order to save water, we can do all of the following things except . A. fully use the washing machine B. repair leaky faucets C. take short showers instead of baths D. turn the faucet off while brushing your teeth 4. Recycling helps to reduce waste because . A. plants need to develop B. waste can be recycled and reused C. a person can do it in his home D. an average man produces compost for plants 5. The word “It” in paragraph 2 refers to . A. cutting down B. the number C. recycling D. effort

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