短语词组短語reverse graded bedding 反序粒層理content graded bedding 含量遞變層理double graded bedding 雙重粒級層biogenic graded bedding 生物粒級層;[古生]生物遞變層理rhythmic graded bedding 韻律性遞變層理reversely -graded bedding 倒轉分級層 返回 graded bedding