[biàn zhì]
(变坏) go bad; deteriorate
become morally degenerate
蜕化变质
The food undergoes no deterioration in the tropics.
这种食品在热带地方不会变质。
The milk has turned sour.
牛奶变质了。
[地](变质作用) metamorphism; [冶] (加入微量元素以改善其组织和性能) modification; [生] (退化、变质) degenerescence; degeneration