Wheat is the first staple grain crops in the world. Arid is one of the major limiting factors for wheat production.

小麦是世界第一大粮食作物，而干旱是小麦稳产、增产的主要限制因素之一。

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Filburn, upheld a Roosevelt-era law limiting grain production to prop up prices even when the farmer in question was growing grain entirely for his own consumption.

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The AHA still recommends eating five servings of fruits and vegetables and six servings of grain every day, as well as limiting fat, salt, cholesterol and alcohol.

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