If you’re a Premium member, you will now see the following two options displayed when you finish a ‘Largest Cities’ quiz (the regular ones, not those by latitude, within a state, etc).
If you click ‘Add Answered To Learned List’ the answers you got right will be added to the cities which appear as ‘Memorized’ on the Cities Learning quiz for that geography. Clicking on ‘Remove Missed From Learned List’ will take any answers you missed which are on your ‘Memorized’ list and move them back onto the learning map so you can study them again.
Darin