短語詞組短語land amelioration 土地改良continuous amelioration 持續(xù)改進(jìn)grassland amelioration 草地改良amelioration design 改進(jìn)設(shè)計quality amelioration 質(zhì)量改進(jìn)amelioration operator 改進(jìn)算子amelioration efficiency 改良效果amelioration degree 改善程度cultivational amelioration 耕作土壤改良 返回 amelioration