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huynhchina
2 năm trước
Cho 7,25 gam một anđehit đơn chức X tác dụng với lượng dư dd AgNO3/NH3 (phản ứng xảy ra hoàn toàn), thu được 27 gam Ag. Nhận xét nào dưới đây đúng? A. X có 4 nguyên tử H B. X là hợp chất andehit không no C. X có 2 nguyên tử cacbon D. X có 9 liên kết xich-ma (𝛿) trong phân tử
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Exercise 5: Choose the best option to fill in the blank. 1. There used to be fewer people and .................. on the roads. A. roofs B. helmets C. helicopters D. vehicles 2. Do you know the .................. in the UK is to keep to the left? A. traffic light B. traffic rule C. traffic jam D. speed limit 3. It is dangerous to ride a motorbike without a .................. A. helmet B. triangle C. tricycle D. circle 4. In Hanoi, during rush hour, some road users ride their motorbikes on the .................. A. driving licence B. lane C. pavement D. seat belt 5. Traffic is terrible during the .................. when everyone is in a hurry to get to work or come back home. A. traffic light B. road sign C. traffic rule D. rush hour 6. The ................ for motorcycles is 40 km/h in towns and 60 km/h outside urban areas. A. speed limit B. driving licence C. traffic rule D. traffic light 7. You must .................. the traffic rules in order to avoid accidents. A. park B. obey C. reverse D. warn 8. It takes us more than three hours to drive across those .................. roads. A. wide B. safely C. right-handed D. bumpy 9. You need a driving licence to .................. A. drive a car B. ride a bike C. get on the bus D. get off the train 10. The large supermarkets in Vietnam often let you .................. free. A. park B. obey C. warn D. find 11. Some vehicles beep when they .................. to warn those behind. A. ride B. reverse C. drive D. sail 12. After school, children queue up and wait for the bus .................. on the pavement in front of the school. A. safe B. bumpy C. safety D. safely

VIII. Put the correct form of the following verbs in the correct blanks to complete the letter. not get back take decide find hire dive do arrive get up not be stop go Dear Ha, Hi, I’m on holiday in Nha Trang with the Robinson. We ..................... (1) last Saturday. The first day the weather ..................... (2) very nice, so we ..................... (3) some sightseeing. I .................. (4) lots of photographs. On Monday, we .................. (5) a car and .................. (6) out into the country. We ..................... (7) for lunch at a lovely little village and then in the afternoon we ..................... (8) a beautiful beach. Last night ..................... (9) to the cinema. We ..................... (10) till about 11p.m, so we ..................... (11) late this morning and we ..................... (12) to have a relaxing day by the hotel swimming pool. So that’s where I am now. Love, An IX. Fill in the blank with a suitable word open forget come be bring have turn wait make Dear John, Come and see me next weekend. I’m staying in a house by the sea. Don’t (l) to bring your swimming costume with you! It isn’t difficult to find the house. When you get to the crossroads in the town, (2) right and drive to the end of the road. (3) careful because it is a dangerous road! (4) some warm clothes with you because it is cold in the evenings here. If I am not at home when you arrive, don’t (5) for me. The key to the house is under the big white stone in the garden. (6) the front door and (7) yourself a cup of tea in the kitchen! (8) a good journey! Best wishes, Vinh

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