合肥天择职业培训学校:翻译个句子，顺便说以下for是什么用法.however在这里是修饰前句还是后句？

然而广义利己主义的立场几乎是毋庸质疑的,因为一个人总会希望自己的帮助行为可以得到回报,但他无法肯定的是为了得到回报总是帮助别人的前提.
The position of universal egosim is almost irrefutable, however,for one can always think of rewards for an act of help but can not guarantee that there rewards were the basis of the helpers intentions

翻译具体如下:
however是插入语,翻译的时候可以放到前面去
however 是对整个这段话意思的转折,也就是说However可以放在句首:
However,the position of universal egosim is almost irrefutable for one can always think of rewards for an act of help but can not guarantee that these rewards were the basis of the helpers intentions

For 在这里表示原因 引导原因状语从句

然而,广义利己主义的立场几乎是不可驳倒的,因为一个人对帮助行为总会考虑到去回报, 但却不确定回报是否是帮助人做出帮助时候的动机.

however是插入语,翻译的时候可以放到前面去.

然而广义利己主义的立场几乎是毋庸质疑的,因为一个人总会希望自己的帮助行为可以得到回报,但他无法肯定的是为了得到回报总是帮助别人的前提.

however 是对整个这段话意思的转折,也就是说However可以放在句首:
However,the position of universal egosim is almost irrefutable for one can always think of rewards for an act of help but can not guarantee that these rewards were the basis of the helpers intentions

For 在这里表示原因 引导原因状语从句