Cho n điểm. Vẽ các đoạn thẳng nối 2 trong n điểm đó. Có tất cả 45 đoạn thẳng. Tính n? (Ko vẽ cả hình ra, hãy tính n)

Convert following active sentences into passive forms

1. How many languages do they speak in Canada?

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2. Did Mary buy this beautiful dress?

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3. Are you going to help her solve that problem?

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4. Have you turned off the air-conditioner?

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5. When will you hand in the required assignment?

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6. How many times have i told you to keep silent in class?

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7. Should i send a complaint letter to the mayor?

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8. Had you come to any conclusions before we came?

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complete the sentences, using a relative pronoun

1. The neighbour makes a lot of noise walking around. His flat is above mine

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2. The local market sells excellent local produce. It is a two-minute walk from my flat

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3. John is speaking to his boss. His boss is a famous writer

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4. I like the town. You live there

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5. I like the painting. It is in this room

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6. The man was sick. He looked very pale

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7. He was sitting in the emergency room. It was very crowded

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8. A nurse was nearby. He called to her

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9. The nurse called a doctor. He came quickly

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10. She gave the man an injection. It made him go to sleep

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