You've finished all the Oddball sets for this selection.
Oddball is built to test why three terms belong together, not just whether you recognize a definition — that's exactly the kind of reasoning the AP exam rewards when it asks you to apply a concept to a new example rather than just define it. Filter by unit while you're still learning new material, then switch to "All Units Mixed" once you want a cumulative challenge closer to test day. Always read the explanation before moving on, even after a correct guess — sometimes the term you picked and the real oddball look similar for entirely different reasons, and that's the distinction worth catching. If a unit keeps giving you trouble here, that's a good signal it's worth another pass in Flashcards or the Glossary.