degradation

n.降低，恶化

deforest, deforestation, deform, deformation, deformed, deformity, defraud, defray, defrayal, defrock, defrost, deft, deftly, deftness, defunct, defuse, defy, deg, degenerate, degeneration, degrade, degree, degrees, dehumanization, -isation, dehumanize, dehumanize, dehumanise, dehydrate, dehydration, deification, deify, deign, deism, deist, deity, deja vu, deject, dejected, dejectedly, dejection, dekko,