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Dùng 3 ròng rọc cố định và 3 ròng rọc động để đưa một vật lên cao thì đc lợi bao nhiêu lần về lực và thiệt bao nhiêu lần về đường đi. Vẽ hình. Giúp mik vs trả vote 5 sao nha!
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VII. Read the text. Then choose the right answer A, B, C or D. Last year, we had a nice holiday. My friend and I went to the seaside for a month. I had been to the seaside several times before, but this was the first time for my friend. Naturally, it was the great event for him. Finally, the day came. It was a fine morning. We got up very early because we wanted to leave home after breakfast. We made the journey by car. We reached the seaside at noon. We spent many hours on the beach. We enjoyed making castles and channels in the sand. People said we ought to spend at least a few weeks here. If we could stay longer, so much the better. 39. How long did the writer and his friend spend at the seaside? A. week B. A few weeks C. A month D. A few months 40. Who went to the seaside the first time? A. The writer B. The writer and his friend. C. The writer's family. D. The writer's friend. 41 . What was the weather like on the day they started their journey to the seaside? A. It was bad. B. It was rainy. C. It was snowy. D. It was nice. 42. How did they travel to the seaside? A. By car B. By train C. By bus D. By air 43. When did they reach the seaside? A. At 8 o'clock B. At 12 o'clock C. At 4 p.m D. At 9 p.m 44. What did they enjoy making in the sand? A. They enjoyed making castles. B. They enjoy to make castles and channels. C. They enjoyed to make castles and channels.D. They enjoyed making castles and channels. 45. The word "here" in the sixth line means "______" A. at the seaside B. castles C. channels D. in the sand 39. 40. 41. 42. 43. 44 45.

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