第一句没有语法错误。
第二句中 which relates to 可以用 related to 替代。
第三句,使意动词 如have ,make, help, let 一般都不接不定式
第四句语法上没错,可是句式太繁琐 不符合英语习惯表达。不是所有修饰名词的从句都能用 in which 引导。
句子应翻译为:
this reaction could, in the future, become a kind of survival instinct of people learning to avoid pain.
in the future 也可放在句末 :this reaction could become a kind of survival instinct of people learning to avoid pain in the future.
2.直接用related后置定语好一点
3.不用to do的,have,let,
4.不用in which ,用which 做的是ability的定语从句,修饰的是名词
i live in the place .this is the place which i live in 给你个例子看一下 这里的in which 可以换成where 后面的in 就不用了