n.渐变；阶段；等级；刻度；元音交替
I have noticed the subtle gradation in colour in this painting. 我已经注意到这幅画中色 彩的渐变。
A good actor can express every gradation of feeling from joy to grief. 一名好演员能够表现出由快乐至痛苦的每一阶段的感情变化。
It was hard to understand all the minute gradations of their bureaucracy. 很难弄清楚他们那套官僚体制全部细微的层次分别。
n.降格；堕落；退化
adj.有等级的；渐次的；浓淡法上的
n.逆行；后退；倒退
n.加积(淤高；浚填)
adj.加积的(淤高的；浚填的)
n.生物降解
