There was a time   曾经   I thought,that you did everything right   我以为你所做的一切都是正

问题描述:

There was a time   曾经   I thought,that you did everything right   我以为你所做的一切都是正

once 或 ever 吧

楼主是要填入一个单词么?则答案是:when.
“there was a time + when从句”这是一个固定句型,意思就是“曾经/一度...”.