digression/interruption.
-to continue the main discussion...
-going back to what i was saying...
-i mentioned earlier...
阐述两个要点间的联系
-as i said earlier/before...
-you will recall that earlier i said...
-you may have been wondering why i said...
-when i was talking about this point earlier i said...
-in my introduction i said...
-five minutes ago i said...
-you may have noticed that...
-i mentioned earlier that...
-let me pick up a reference made earlier to...
总结
-to summarize...
-briefly, then...
-we have seen that...
-the main points, therefore, are...
-if i can summarize what i have said so far...
-if we can take stock for a moment...
-thus we can see...
-it must now be clear that...
-i've been attempted to explain here that...
-so, to sum up...
-to recap, then, ...