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Một xe chuyển động trên đoạn đường AB , đi được 1/3 đoạn đường đầu thì xe bị hỏng phải dừng lại sửa chữa hết 1/2 thời gian đã đi. Nếu muốn đến nơi như dự định ban đầu thì trên đoạn đường còn lại xe phải đi với vận tốc bao nhiêu so với vận tốc v1 ban đầu
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Trả lời + Giải thích giúp em Many wild animals are now in danger of _____. A. death B. disease C. survival D. extinction 2. If doctors could discover the ____for cancer, they could save millions of people's lives. A. success B. reason C. remedy D. effect 3. One of the worst _____ that mankind has ever had is cancer. A. situation B. diseases C. conditions D. accidents 4. We would _____ lung cancer if people give up smoking. A. finish B. get rid of C. kill D. cancel 5. Mark went to the party _____ he wasn't invited. A. because B. in spite of C. however D. although 6. This shirt is _____ small for me to wear. A. so B. very C. too D. most 7. Thousands of people _____ being employed in the textile industry. A. have B. are C. has D. is 8. If she _____ so conceited, we'd like her more. A. weren't B. isn't C. hasn't been D. wouldn't be 9. I received a lot of presents _____ my eighteenth birthday. A in B. on C. at D. during 10. Nam feels _____ because he did very badly on his last test. A. happy B. happily C. unhappy D. unhappily 11. I like listening to the music programme _____ the radio. A. above B. in C. through D. on 12. She's scared of living _____ her own in a big city. A. by B. on C. for D. in 13. There are more than 6000 living languages, _____ which English is the most widely used. A. of B. for C. about D. on 14. English is regarded as an effective _____ of international communication. A. method B. solution C. result D. medium 15. It is said that _____ is better than cure. A. health B. remedy C. prevention D. surgery 16. You can use my telephone _____ you pay for the calls you make. A. as long as B. although C. however D. whereas 17. I liked the book very much _____ I didn't have enough money to buy it. A. because B. while C. but D. unless 18. Life in the city is much more _____ than that in the country. A. expense B. expenses C. expensive D. expand 19. We were planning to have a picnic but _____, it was raining heavily. A. fortune B. fortunately C. fortunate D. unfortunately 20. The _____ is the place where a particular species of animals is normally found. A. habitat B. surrounding C. region D. area 21. The _____ of this city has increased rapidly in the recent years. A. number B. population C. crowd D. total 22. The girl _____ photo was in the paper today lives in our street. A. who B. whom C. which D. whose 23. Have you got a _____ carpet than this? A. cheaper B. cheap C. cheapest D. the cheapest 24. When I _____ my new house, I _____ for a telephone. A. was buying/ asked B. were buying/ were asking C. bought/ asked D. bought/ was asking 25. She _____ to go on a diet. A. advised B. advises C. advising D. was advised 26. Alice started playing tennis _____. A. for 2 years B. since 2 years C. 2 years ago D. in 2 years 27. What would happen to our lives if the forest did not _____. A. destroy B. exist C. take place D. occur 28. Many species of rare animals have already become _____. A. disappeared B. dangerous C. extinct D. decayed 29. She will be disappointed _____ she gets the jobs. A. but B. unless C. because D. if 30. We don't like that film. It is very_____. A. bore B. bored C. boring D. boredom

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