Chuyển những câu sau sang câu bị động:
11. My father waters this flower every morning
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12. John invited Fiona to his birthday party last night.
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13. Her mother is preparing the dinner in the kitchen.
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14. We should clean our teeth twice a day.
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15. Our teachers have explained the English gramar.
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16. Some drunk drivers caused the accident in this city.
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17. Tom will visit his parents next month.
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18. The manager didn't phone the secretary this morning.
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19. Did Mary wear this beautiful dress last night?
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20. I won't hang these old pictures in the loving room.
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