Centuries ago, man discovered that removing moisture from food helped to preserve it, and that the e...

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Đoạn văn mở đầu đã nói nên bao quát nội dung của cả bài “Centuries ago, man discovered that removing moisture from food helped to preserve it, and that the easiest way to do this was to expose the food to sun and wind. In this way the North American Indians produced pemmican (dried meat ground into powder and made into cakes), the Scandinavians made stock fish and the Arabs dried dates and apricots...”

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