短語詞組短語flute rill mark 槽形細流痕bifurcating rill mark 分叉狀流痕branching rill mark 分枝狀流痕lobate rill mark [地質(zhì)]舌狀流痕conical rill mark 錐形流痕tooth -shaped rill mark 齒狀流痕 返回 rill mark