Can this circuit oscillate?
They made a mistake. Its a negative feedback loop.

in fact I would urge you to challenge your Prof.

If you put a sweep generator on the U1 + input instead of ground each op amp becomes a unity gain + voltage follower and since the output is fed back to the Vin- is the same as the input there is NO feedback current (zilch , nada , nothing)  , hence RC does NOTHING. and with no sweep the output is same as Vin+ on U1 .. meaning 0V.

Beware if you do, he may invite to be a post grad student for your intelligent question. and if he doesn't understand refuse his offer. (ROTFL)