大部分在古生代岩层中发现的化石都是没有脊骨的无脊椎动物，例如珊瑚、软体动物和三叶虫。
Most of the fossils seen in Paleozoic rocks are invertebrate animals lacking backbones, such as corals, mollusks and trilobites.
因为3亿年前山洞是在水底的，山洞总的石灰石里有许多的贝壳，骨骼和珊瑚化石。
Because it was underwater 30 million years ago, the cave is made from limestone composed of fossilized shells, skeletons and coral.
预计到2050年，由于化石燃料燃烧释放的二氧化碳溶于海水，海水变酸，全球范围的珊瑚礁将急剧缩减。
2050 projected year when coral reefs worldwide will shrink because of increased ocean acidity as atmospheric carbon dioxide, from burning fossil fuels, dissolves in seawater.
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