As a result, few companies are now supporting the kind of long-term research on which

As a result, few companies are now supporting the kind of long-term research on which US leadership has been founded.
请问这个定语从句 which US leadership has been founded的先行词是什么？为什么要介词on, 是介词提前吗？

as a result of 和result from有区别吗？ sustained as a result of an infringement as a result 和as a consequencequ区别 用as well as,such as,as a result组成一段话 用as well as,such as,as a result一段短文 用as well as,such as,as a result写一篇关于自己兴趣的作文 as a result of和because of的用法区别 What damage can be caused as a result of bushfires? as a result of 和 because of 区别 as a result什么意思（句守）？？