Of, belonging to, or being the geologic time, system of rocks, and sedimentary deposits of the fifth period of the Paleozoic Era, characterized by the submergence of extensive land areas under shallow seas.是什么意思_Of, belonging to, or being the geologic time, system of rocks, and sedimentary deposits of the fifth period of the Paleozoic Era, characterized by the submergence of extensive land areas under shallow seas.在线翻译_英语_读音_用法_例句