touch on

The article touched on the main problem.

文章提到主要问题。

I want to touch briefly on another aspect of the problem.

我想简单谈下这个问题的另。

In his lecture on geology, he touched on the subject of climate.

他关学的报告中, 也涉及气候问题。

He touched me on the arm.

他碰了下我的手臂。

Such actions touch on betrayal.

这种行为近乎背叛。