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phamthanhhung176
2 năm trước
tìm tập hợp số nguyên n biết a,3n chia hết cho n-1 b,2n+7 là bội của n-3 n+2 là ước của 5n-1 n-3 là bội của n^2+4
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III. Fill in the blank with the most suitable prepositions: 1. Liz went _____ Nha Trang ______ summer vacation. 2. What are you thinking ______? 3. Nam talked ____ his friends _____ his recent vacation. 4. They returned ____ Hanoi last week. 5. She made a blue dress ____ her daughter. 6. The cap has a picture of a dolphin ____ it. 7. After the holiday they returned to Hanoi ____ plane. 8. They arrived home ______ the evening. 9. My mother takes care ________ the family. 10. I smiled _____ the child and said “hello” 11. Milk is good _____ your health. 12. She is always worried ________ her children. 13. Most children are scared ______ seeing the dentist. 14. The dentist looked ____ my teeth. 15. Will they come _____ dinner tonight? 16. There was a wide collection ____ vegetables ____ the stall. 17. The bus stopped ___ the bus station. 18. She added a little salt ____ the spinach. 19. Hoa set the table _____ plates, bowls, chopsticks, spoons and glasses. 20. You should eat plenty ____ fruit and vegetables. 21. I like taking part ____ sports. 22. There was a walking competition ____ children last night. 23. The number _______ participants increases every week. 24. You should listen _____ the pool lifeguard. 25. I don’t have my pocket ____ me. 26. Are you aware _____ the time? 27. There is a play _____ the Youth Theater tonight. 28. Are you free _____ Monday? 29. We should wash our hands ______ meals. 30. Very few Vietnamese people had TV sets _____ 1960s. 31. The street is full of traffic from morning ____ night. 32. Some people gathered outside the house and watched TV _____ the window. 33. Don’t forget to brush your teeth ____ every meal. 34. I was at the seaside ____ my summer vacation. 35. We will meet _____ six o’clock ______ Monday evening. 36. You should brush your teeth _____ every meal. 37. Hoa usually talks about her day _________ dinner. 38. The burglar got into the house _____ the window. 39. She lived ________ America ____ 1966. 40. Remember to wash your hands ____ meals. 41. What is ____ TV today? 42. There aren’t many good programs ____ teenagers. 43. Ho Chi Minh died ____ Hanoi _____ 1969. 44. I’m really interested _______ history. 45. He was famous _______ the fairy tales 46. Their ages range ______ twenty _____ forty. 47. Charles Dicken was born ____ February 17th 1812 ___ a poor family. 48. Are you very good ____ English? 49. They do not depend ____ tourism to live. 50. The children are growing ____ fast.

5 sao lun : IX Read the passage. There are three main (1) ……………… of pollution: air pollution, water pollution and noise pollution. Air, which is the most important element of our environment for our (2) ……………………, can be polluted in many ways. Smoke in the air from mills, factories and industry (3) …………………… carbon, monoxide, carbon dioxide, and methane, which are all poisonous gases. This leads (4) …………………… health problems like asthma and lung diseases, and the thinning of the ozone layer, which (5) …………………… us from harmful UV ray. China, the USA, Russia, India, Mexico and Japan are the world leaders in air pollution (6) …………………… Water is also polluted by the discharge of commercial and industrial waste. Sewage in drinking water is another (7) …………………… 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 (8) ……………… headaches, tension, (9) ……..………… 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 (10) …………………… noise pollution. Choose the best answer (A, B, C or D). 1. A. types B. kinds C. models D. both A & B 2. A. survival B. survive C. surviving D. survived 3. A. includes B. include C. contains D. contain 4. A. in B. into C. to D. from 5. A. prevents B. protects C. avoids D. hides 6. A. emissions B. emitted C. emission D. emitting 7. A. effect B. cause C. result D. consequence 8. A. causes B. leads to C. results in D. all are correct 9. A. brain B. mind C. head D. mental 10. A. told B. called C. said D. mentioned Answer the questions below. 1. What are the examples of health problems caused by air pollution? 2. Why is sewage in drinking water another cause of water pollution? 3. What does the writer says about the noise of vehicles, mills and factories? X Read the passage. Answer the questions below. Scientists have discovered that the ozone layer is getting thinner. Some predict that the sun’s rays will cause a sharp increase in deaths from skin cancer over the next fifty years. These harmful rays can also damage the eyes, create wrinkles, and cause other health problems. The stratosphere contains a form of oxygen called ozone. Ozone is a molecule composed of three oxygen atoms. The chemical formula of ozone is 03. Oxygen molecules make up about 21% of all gases in the Earth’s atmosphere. They consist of two atoms of oxygen and are labeled 02. Most ozone found in our atmosphere is formed by an interaction between oxygen molecules and ultraviolet radiation (UV) from the sun. When ultraviolet radiation hits an oxygen molecule, it may cause the molecule to break apart into single atoms of oxygen. These single atoms are very reactive, and a single oxygen atom can combine with a molecule of oxygen to form ozone. 1. What do people say about the rate of deaths from skin cancer in the future? 2. How many oxygen atoms are there in a molecule? 3. What elements participate in the formation process of ozone? 4. What happens when an oxygen molecule and an ultraviolet radiation hit each other? 5. What is the feature of single atoms?

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