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hieurookie
2 năm trước
Câu 4: Một ô tô chạy trên đường thẳng đi từ A đến B có độ dài quãng đường là s. Tốc độ của ô tô trên nửa đầu của quãng đường này là 25 km/h và trong nửa quãng đường cuối là 30 km/h. Tốc độ trung bình của ô tô trên cả đoạn đường AB là bao nhiêu ? Lưu ý: Làm bài đầy đủ các bước sau: + Tóm tắt. + Lời giải. + Công thức. + Thế số, tính toán ( đơn vị).
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1. Read the passage and answer the questions below. Mr. Bruhn, 62, is a good and happy man. He and his wife, Alice 63, have worked hard all their lives on their farmland, so rich that, although it has been farmed more than a hundred years, the black topsoil is still more than a foot thick. This spring Mr. Bruhn planted 80 acres of corn, 35 acres of oats and 35 of hay land. The farm has around 300 hogs and 150 steers. Mr. Bruhn raises the hogs himself and purchases the steers. Mr. Bruhn and his wife work very hard, though now, there are tractors and combines and corn pickers, planting oats and corn and feeding his hogs and cattle. He is, in many ways, typical of hundreds of thousands of other American farmers. Yet, he is untypical, for he does not seek, nor is he impressed by the new ways, the massive machines and the continued expansion of farms. This is not to say he is a man who lives in the past. Just because his life is marked by proportion and balance. And also, he is a man without greed. 1. How old is Mr. Bruhn's farm? 2. What did Mr. Bruhn do on his farm this spring? 3. What machines used for farming does he have on his farm? 4. Is Mr. Bruhn untypical of hundreds of thousands of other American farmers? Why or why not?

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