Beneath the Sahara are huge aquifers, basically a sea of fresh water, that's perhaps a million years old filtered through rock layers.

撒哈拉沙漠下面是巨大的含水层，基本上是一片淡水的海洋，那可能是经过岩石层过滤的，已经有一百万年历史。

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He pulled out this dusty old rock tumbler.

他拖出了这个布满灰尘的旧磨石机。

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The 4.6 billion-year-old rock is a sample of the solar system from before the birth of our planet.

1969年，一颗陨石落到了澳大利亚的莫奇森（Murchison），这块46亿年的岩石地球诞生之前的太阳系样本。

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Today we explain a very old saying that has had a big influence on rock-and-roll music.

VOA: special.2009.06.21

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The 26-year-old rock 'n' roller suffers from cystic fibrosis, which fills her lungs with bacteria-infested mucus.

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