1)ground ladder,落地梯子2)free-standingfloorcreel,落地筒子架3)standard electronic organ,落地式电子琴4)No Death of a Grain of Wheat Falling into the Earth,落地的麦子不死5)community gradient,群落梯度6)ladder,梯，梯子
用法和例句
The distribution trends of species richness indices,species diversity indices and species evenness indices along the community gradient were almost the same.