Eek!
Class scenes are such a plot dragger, I hope they're limited

I've see such scenes sap the life from a plot by taking several days to resolve
Remember in school the greatest fear is that the clock has stopped and the bell will never ring
"No! Not the Infinity effect"

It's like the required lecture where the speaker has no set time limit
You sit there realizing that He/She is now repeating themselves and seem gifted with the Stamina of an Olympic Marathoner