我想他们问我，是因为他们相信一个老师应该知道答案。

I assume that they ask me because they believe a teacher should know the answers.

youdao

你应该知道，因为我刚刚读过。

I ought to know. I just read it.

youdao

你明白我的确切意思，因为有很多次，你本来知道应该做什么，却理直气壮地什么也不做。

You know exactly what I mean because there have been many times when you've known what you should be doing but have rationalised yourself into doing nothing.

youdao