I say - if you want to kill it completely (I would also find more expressive words that better describe it), then speak for the whole 45 minutes. We at university are not able to keep our attention for more than ten or twenty minutes at most. So I told them to tell the basic info, characteristics and then ideally use the textbook, atlas, workbook to assign tasks to pairs or a more mass form.
We at university are not able to keep our attention for more than ten or twenty minutes at most.