表示变化和不变的词 get turn go become (变化) keep stay remain（不变）是什么意思

get turn go become他们是表示变化的词：
比如,The day gets longer.白天时间变长了.
The milk goes bad.牛奶坏点了（变酸了）.
That man becomes brave.那个人变的勇敢了.turn,也是,这四个表示变化的.
而
keep stay remain有持续,维持,保持的意思,就不变或者变化很小喽.
如Keep silent,please. 请保持安静.
The water surface remains peaceful.水面无一丝波纹.