Question

there was no reason to be怎么理解

Answer 1

There was no reason to be...没有理由......。例如：
I was a bit nervous before I arrived here, but there was no reason to be （nervous）. 在到这儿之前，我有点紧张，但是没有理由紧张。
I think there was no reason to be afraid. 我觉得没有理由害怕。
I have told you three times and there is no reason to be late. 我已经告诉你们三次了，没有理由迟到。

Answer 2

这个句子肯定是承接上文而来的。这种情况没有上文翻译不了， 因为be动词后面省略了上文中用到的一个词