If so, you must have put stamps on the letters before you sent them. So how did people receive letters before stamps were invented, and who came up with the idea of using stamps?

如果寄过，那你一定在寄信之前在信封上贴上了邮票。

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Additional evidence of food stamps' role in weight gain came when the researchers looked at how people's BMI changed before, during and after they were on food stamps.

另外一个可以证明食物券在体重增加中的作用的证据是研究者分析了人们在使用食物券前，使用期间和使用后的体重变化。

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On Chinese stamps it is out of imagination to have something like US brightens the world on the US stamps.

在中国邮票上出现美国邮票上诸如“美国照耀全世界”这样的字眼是不可想像的。

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Such experiments ended. Cuba and the United States both honored Clara Maass on postage stamps.

VOA: special.2009.01.27

You kept your Social Security card and you pasted stamps on it that proved that you paid it.

你取得社会保障卡,并将邮票贴在上面,以此来证明你已支付过钱。

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We also know, anecdotally, of how, in the past decade, millions more Americans have become dependent on food stamps and on jobless benefits (not just for the six-month normal duration, but now for as long as two years).

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Their work includes meeting arcane record-keeping requirements on workers' pay and conditions, and getting the right stamps on the right bits of paper for the sleepy customs service.

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Then there are stories of PhD on food stamps and the list goes on and on.

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