Vật AB cao 5cm đặt trước một thấu kính hội tụ có tiêu cự 12cm. Biết AB vuông góc trục chính, A nằm trên trục chính và cách thấu kính một khoảng 8cm. a) Dựng ảnh A'B' của AB tạo bởi thấu kính? b) Tính khoảng cách từ ảnh đến thấu kính và độ cao của ảnh?

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II. Writing samples: Natural disaster 1. NghệAn Province / badly / affect / when / typhoon / hit / area / last night. …………………………………………………………………………………………………………………………… 2. The storm / begin / around 11p.m / and / rage / throughout / night. …………………………………………………………………………………………………………………………… 3. Dozens / people / be / seriously injured / and / hundreds / others / be / left homeless. …………………………………………………………………………………………………………………………… 4. The severe winds / cause / extensive damage / property. …………………………………………………………………………………………………………………………… 5. The government / already / send / rescue equipment / NghệAn Province / well / food / medical supplies. …………………………………………………………………………………………………………………………… 6. The weather bureau / issue / flood warnings Nghệ An / nearby provinces / because / heavy rain / expected / continue / over / next few days. …………………………………………………………………………………………………………………………… Air pollution: 1. Air pollution/ the release/ particulates, biological molecules or other harmful materials/ Earth’s atmosphere. .……………………………………………………………………………………………………… 2. It/ cause/ diseases and death/ humans, damage to other living organisms. .……………………………………………………………………………………………………… 3. There/ some causes of pollution such/ burning of fossil fuels, agricultural activities, exhaust from favorite and industries,mining operations / indoor air pollution. .……………………………………………………………………………………………………… 4. These causes/ lead/ so many effects such as respiratory/ heart problems, globalswarming , acid rain, effect/ wildlife and depletion /the ozone layer. .……………………………………………………………………………………………………… 5. These effects/ damage/ human life/ dramatical. .……………………………………………………………………………………………………… 6. We need/ prevent air pollution/ much as possible/ create a better habitat. .……………………………………………………………………………………………………… Water pollution: 1. Water pollution/ the contamination/ bodies/ water/ such/ lakes/ rivers/ oceans/ ground water. .……………………………………………………………………………………………………… 2. There / two different ways/ which pollution /occur. .……………………………………………………………………………………………………… 3. If pollution/ come/ from a single location, such as industrial waste into lakes and rivers, sewage from households, pesticides and herbicides, it is/ know/ as point-source pollution. .……………………………………………………………………………………………………… 4. While pollutants/ storm water and the atmosphere result/ "non-point source" pollution. .……………………………………………………………………………………………………… 5. Water pollution can outbreak /cholera / diseases, even die in human. .……………………………………………………………………………………………………… 6. It also cause/ the death/ aquatic animals and plants and further damage/ the environment. .……………………………………………………………………………………………………… 7. Governments/ have/ very strict laws that help/ minimize/ water pollution. .……………………………………………………………………………………………………… 8. Making people aware /the problem /the first step to solving it. .……………………………………………………………………………………………………… A visit to an English speaking country: 1. I would like/ visit/ Wanaka/ New Zealand. .……………………………………………………………………………………………………… 2. It/ famous/ the natural beauty/ the Puzzling World. .……………………………………………………………………………………………………… 3. I/ take biking and walking tracks /through the park. .……………………………………………………………………………………………………… 4. I/ also/visit/ Illusion Room/ the Leaning Tower .……………………………………………………………………………………………………… 5. I/ think/ a trip/ Wanaka/ relaxing. .………………………………………………………………

1. There are asthma, allergies and other respiratory illness when air pollution happens. Air pollution results……………………………………………………………………………… 2. Eating too much sugar can result in health problems. Eating too much sugar can lead ………………………………………………………………………………… 3. I can’t swim, so I won’t go scuba- diving with Jerry. If …………………………………………………………………………………………………………………… 4. The boys didn’t go swimming because the weather was cold. Because of ……………………………………………………………………………………………………… 5. “I like to do physics experiment”, he said. He said that ………………………………………………………………………………. 6. The area is uninhabitable. The Chernobyl nuclear accident happened. The Chernobyl nuclear accident made. …………………………………………………. 7. The volcano erupted after most people had left. Before ……………………………………………………………………………………. 8. Volunteers have given out food to homeless people. Food ……………………………………………………………………………………… 9. I think you should grow vegetables in the garden. If I ………………………………………………………………………………………… 10. Jack: “Mary, I’m leaving Viet Nam tomorrow.” Jack told Mary that .............................................................................................................................. 11. Acid rain is dangerous. Trees' leaves are damaged. Trees' leaves are damaged because .......................................................................................................................... 12. He asked Mary: “How did you feel when you saw the alien?” He asked Mary ..................................................................................................................................... 13. We turn on the heater all the time. We have to pay three million dong for electricity a month. If we didn’t ............................................................................................................................................ 14. They are going to organise a garden party to raise money for the victims of the flood. A garden party ...................................................................................................................................... 15. “You have to sign the paper again.” She told me. She said to me …………………………………………………… 16. Mr Smith will collect the tickets. The tickets ……………………………………………………….. 17. The noise from the music club is loud, so the residents of the street cannot sleep. Because of ………………………………………………………. 18. She has a headache after work every day. She works in a noisy office. If she didn’t ………………………………………………………. 19. Peter said, “I’m living in London now.” Peter said ..................................................................................................................................................... 20. Tom was at home because his leg was broken. Because of …………………………………………… ……………………………………………………. 21. I don’t have enough time , so I can’t go on holiday this summer. If I ……………………………………………………………………………………………..................... 22. They have built two department stores recently. Two department stores..................................................................................................................................... 23. Bill bought a new computer at the supermarket yesterday. A new computer…………………….………………………………………………………………….…… 24. The polluted water leads to the death of the fish. The polluted water makes……………………………………………………………………………………………… 25. The karaoke bar makes so much noise almost every night. The residents complain to its owner. If the karaoke bar didn’t ............................................................................................................................ 26. People know him as an environmentalist. He ............................................................................................................................................................... 27. People have spoiled this area for a long time. This area ...................................................................................................................................................... 28. John told Chau: ‘ I’m leaving Viet Nam tomorrow.’ John told Chau that ..................................................................................................................................... 29. We can’t see the stars at night. There is too much light pollution. We can’t see the stars at night due .............................................................................................................................. 30. Global warming happens when there is too much carbon dioxide in the atmosphere. Too much carbon dioxide in the atmosphere causes......................................................................................................