Cho a + b + c = 0, chứng minh rằng a^3 + b^3 + c^3 = 3abc Gợi ý: từ a + b + c = 0 ⇒ a + b = -c. Lập phương 2 vế a + b = -c với chú ý 3a^2b + 3ab^2 = 3ab(a + b)

31. My mother took me to the zoo yesterday

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32. Blair invented a color television in 1928.

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33. John gave me these records last week.

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34. Our club holds meetings once a month.

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35. She doesn’t find anything in that box.

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Choose the best answer.

We are looking for ____ place to spend ____ night.

Choose the best answer.

Please turn off ___ lights when you leave ___ room.

Choose the best answer.

I like _____ colorful costumes of ____ ethnic minority people in Vietnam.