touch on

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

他在关于质学报告中, 也涉及气候问题。

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

我想谈下个问题方面。

The article touched on the main problem.

文章提到主要问题。

He touched me on the arm.

他碰了下我手臂。

Such actions touch on betrayal.

种行为近乎背叛。