数十年来，科学家一直都想弄清楚一个问题：火星的大气为何如此稀薄？不过现在人们想搞清楚的问题变成：为什么火星已经完全没有大气了？

For decades, scientists have pondered why Mars has such a thin atmosphere, but now we wonder: why does it have not any atmosphere left at all?

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她仿佛变成了臭氧层，稀薄、无形，千疮百孔。

She became the ozone, which was thin, invisible, and full of holes too.

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臭氧稀薄区域从未变成一个空洞，无论如何。

The thin area has never become an empty hole, however.

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