unchangeable
adj. 不变的；不能改变的；安定的
例句
The doctrine is unchangeable.
这条教义是不可改变的。
《柯林斯英汉双解大词典》
In one study, students were told that their social position in the school is not unchangeable.
在一项研究中，学生们得知他们在学校的社会地位并非不可改变。
Thoughts are not stagnant or unchangeable.
想法不是停滞的，一成不变的。
