We have to get to the root of the problem.

我们必须找到问题的根源。

《牛津词典》

We need to get to the root of the problem before we can solve it.

我们需要先弄清问题的根源，然后才能去解决它。

youdao

This tool allows us very quickly to get to the root of the issue.

这一工具允许我们很快找到问题的根源。

youdao

And by making them go away you don't get to the root of your problem.

虽然恐慌症的症状得以消除,但你却无法找到问题的根源。

耶鲁公开课 - 心理学导论课程节选

First, get to the root of your doldrums by asking yourself what is really bothering me?

FORBES: How To Snap Yourself Out Of A Bad Mood

We'll get to the root cause of it and we'll find out what it is.

CNN: STORY HIGHLIGHTS

Mr Taseer's killer, Mumtaz Qadri, may have acted alone an investigation may get to the root of it.

ECONOMIST: Pakistan's increasing radicalisation