于是不久，农民便有了生产盈余(尤其是风调雨顺时节)，接着农民便可以交换各种不同的物品——谷物、肉、衣服、瓶罐等等。
After a while the farmers could produce surpluses, at least in good times, and the various products of the villagers-grain, meat, cloth, pots-could be exchanged.
建议的每日津贴是1-2微克和良好的饮食来源是肉类（尤其是肝） ，鱼，蛋，奶类生产，强化谷物和啤酒酵母。
The Recommended Daily Allowance is 1-2 micrograms and good dietary sources are meat (particularly liver), fish, eggs, dairy produce, fortified cereals and brewer's yeast.
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