“opoka”的概念、定义、翻译、参考文献-科学参考

单词	opoka
释义	opoka [ō`päk·ǝ] ^PETROLOGY A porous, flinty, and calcareous sedimentary rock, with conchoidal or irregular fracture, consisting of fine-grained opaline silica (up to 90%), and hardened by the presence of silica of organic origin.
随便看	Boys' method Boöpidae Boötes bp bpd B phase bpm BPMC B power supply bps BPSK Bq b quark Br BRA brace brace and bit braced framing braced-rib arch brace head brace key brace pile brace root brachial brachial artery

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