變酸的用法和樣例：
例句
-
如果把牛奶保存在冰箱里，它不會那麼快就變酸。
If you keep the milk in the refrigerator, it won't go sour so quickly. -
牛奶變酸了。
The milk's turned sour. -
牛奶凝結變酸了。
The milk has curdled and become sour. -
炎熱的天氣使牛奶變酸了。
The hot weather has soured the milk.
