Nếu bể không có nước người ta mở một vòi thứ nhất thì sau 6 giờ bể sẽ đầy,còn người ta mở một vòi thứ hai thì sau 9 giờ bể sẽ đầy. Khi bể không có nước người ta mở vòi thứ nhất chảy trong 3 giờ rồi sau đó mở tiếp vòi thứ hai cùng chảy. Hỏi hai vòi cùng chảy tiếp trong bao lâu nữa thì bể đầy?

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Choose the word whose underlined part is pronounced differently from the others 1. A. arrived/ d/ B. believed /d/ C. received/d/ D. hoped/ t/ 2. A. opened B. knocked/t/ C. played /d/ D. occurred/d/ 3. A. rubbed/d/ B. tugged C. stopped /t/ D. filled 4. A. dimmed/d/ B. travelled/d/ C. passed/t/ D. stirred/d/ 5. A. tipped B. begged C. quarrelled D. carried 6. A. tried B. obeyed C. cleaned D. asked 7. A. packed B. added C. worked D. pronounced 8. A. watched B. phoned C. referred D. followed 9. A. agreed B. succeeded C. smiled D. loved 10. A. laughed B. washed C. helped D. weighed 11. A. walked B. ended C. started D. wanted 12. A. killed B. hurried C. regretted D. planned 13. A. visited B. showed C. wondered D. studied 14. A. sacrificed B. finished C. fixed D. seized 15. A. needed B. booked C. stopped D. washed 16. A. loved B. teased /zd/ C. washed D. rained 17. A. packed B. punched C. pleased D. pushed 18. A. filled B. naked C. suited D. wicked 19. A. caused B. increased/Z/ C. practised D. promised 20. A. washed B. parted C. passed D. barked 21. A. killed B. cured C. crashed D. waived 22. A. imagined B. released C. rained D. followed 23. A. called B. passed C. talked D. washed 24. A. landed B. needed C. opened D. wanted 25. A. cleaned B. attended C. visited D. started 26. A. talked B. fished C. arrived D. stepped 27. A. wished B. wrapped C. laughed D. turned 28. A. considered B. rescued C. pulled D. roughed 29. A. produced B. arranged C. checked D. fixed 30. A. caused B. examined C. operated D. advised 31. A. discovered B. destroyed C. developed D. opened 32. A. repaired B. invented C. wounded D. succeeded 33. A. improved B. parked C. broadened D. encouraged 34. A. delivered B. organized C. replaced D. obeyed 35. A. painted B. provided C. protected D. equipped 36. A. tested B. marked C. presented D. founded 37. A. used/ zd/ B. finished C. married D. rained 38. A. allowed B. dressed C. flashed D. mixed 39. A. switched B. stayed C. believed D. cleared 40. A. recommended B. waited C. handed D. designed 41. A. annoyed B. phoned C. watched D. remembered 42. A. hurried B. decided C. planned D. wondered 43. A. posted B. added C. managed D. arrested 44. A. dreamed B. neglected C. denied D. admired 45. A. admitted B. advanced C. appointed D. competed 46. A. announced B. apologized C. answered D. argued 47. A. complained B. applied C. compared D. polished 48. A. booked B. watched C. jogged D. developed 49. A. contributed B. jumped C. introduced D. vanished 50. A. whispered B. wandered C. sympathized D. sentenced