There is no fixed rule.
没有一成不变的规则。
the steady tick of the clock;
钟表一成不变的滴答声;
nothing is seen as unchangeable.
没有什么是一成不变的。
There are no hard-and-fast rules for success.
通往成功没有什么一成不变的规则。
yet English words do not stay the same.
但英语的词汇并不是一成不变的，
This is by no means a regular rule.
这并不是一成不变的规律。
Change happens/takes place all the time; nothing stays the same for long.
事物总是不断变化的，没有一成不变的东西。
It is a nearly static theory.
这是一条几乎一成不变的理论。
The brain is by no means immutable, even in adulthood.
大脑绝对不是一成不变的，即便是成年之后。
Culture will never remain static.
文化并不是定型的，也绝不是一成不变的。
Life is a way of ever-becoming, not a way of becomed!
生命是一个永远持续形成中的方式，而不是一成不变的既成公式！
the inalterable routine of a physician.
内科医生的一成不变的诊治程序
Nothing is not changing / Nothing is unchangeable
一成不变的东西是没有的
Nothing is changeless.
一成不变的东西是没有的。
This distinction isn't hard and fast.
这样的分类并非是一成不变的.
Where was the room for an absolute or a conventional morality?
哪有什么绝对的或者一成不变的美德？
I don't like to sit and look at the same stage scenery one act after another.
我不喜欢—幕接一幕地坐着看这一成不变的布景。
I suspose nothing ever stays the same.
我想没有什么事是一成不变的。