Though only the ninth most abundant element on Earth, it represents about 75% of all matter in the universe.

虽然氢在地球上的丰度只占第九位，但占宇宙中所有物质质量的75%。

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Though only the ninth most abundant element on Earth, it represents about 75% of all matter in the universe.

虽然氢在地球上的丰度只占第九位，但占宇宙中所有物质质量的75%。

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