There was just one question _ (leave)

问题描述:

There was just one question _ (leave)
答案为什么是left不是to leave吗

过去分词做后置定语,“只剩下最后一个问题了”动词不定式不也可以做后置定语吗?但是 to leave 在这里意思不恰当,如果改成to answer 就可以,“只有一个问题需要回答”。