现在设想你的笔记本电脑比一个牛皮纸信封或者你手中的手机还薄。

Now think of your laptop, thinner than a brown-paper envelope, or your cellphone in the palm of your hand.

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注意：如果把情书装在马尼拉纸信封（manila envelope类似于牛皮纸信封——译者注）里的话，那么就别指望你们关系会更进一步了。

WARNING- if you send a love letter in a manila envelope, expect your relationship to end soon

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信封厂使用很多不同类型的纸张，从顶级的犊皮纸到牛皮纸。

Envelope factories use many different types of paper, from top quality vellum to craft paper.

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