请求高手帮忙看看语法，不胜感激！

slglueck

One characteristic common to unsuccessful good innovations has been that, even with extensive government support, they often have not been technologically adapted or culturally acceptable to the people for whom they had been developed.

此句话中划线部分后为何没有动词的过去分词？

jsf22

不明白楼主的意思，一定要有什么过去分词吗？

句子的主干是：One characteristic ... has been that ... 主系表结构