短語詞組短語quality backwardness 質(zhì)量追溯backwardness advantage 后發(fā)優(yōu)勢Not Backwardness 不后退science backwardness 科學落后relative backwardness 相對落后Technological Backwardness 技術(shù)落后Curriculum Backwardness 教學落后method backwardness 手段落后 返回 backwardness