touch on

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

我想简单谈一下这个题的另一方面。

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

他在质学的报中, 也涉及题。

The article touched on the main problem.

文章提到主要题。

He touched me on the arm.

他碰了一下我的手臂。

Such actions touch on betrayal.

这种行为近乎背叛。