帮我分析下语法an undulating plain some 400km across formed of gently folded upper mesozoic nonmarine sediments including red-beds
问题描述：
帮我分析下语法
an undulating plain some 400km across formed of gently folded upper mesozoic nonmarine sediments including red-beds
答
这不是句子 是一个 名词短语 an undulating plain 是名词 some 400km across是定语 formed of gently folded upper mesozoic nonmarine sediments including red-beds是过去分词短语作定语 短语意思 由 地表层稍微折...