In his speech he was only able to touch on a few aspects of the problem.

他在演讲中只能涉及这个问题的几个方面。

Sometimes even a light touch on the face is enough to trigger off this pain.

有时甚至在脸上轻摸一下也足以引发这种痛苦。

So I'll take a moment and touch on that.

所以我会花点时间来聊聊。

Though I do touch on the word simple towards the end.

虽然为此我提及了simple这个单词。

I will touch on those cases in the column as well.

在本专栏文章中我将略微谈到这些案例。