diasdyassicpermian periodpermian system二叠纪 二叠系: dias; dyas二叠纪;二叠系: dyassic二叠系的: dyassic; permian石炭二叠系: permo-carboniferous system石炭系及二叠系: anthracolithic system下载手机词典可随时随地查词查翻译