• Click a topic (above).
• Within a topic, each screen presents six question boxes and six answer boxes (randomly positioned). Drag a question box to its correct answer box; or, sequentially click: first, on the question box and then on the answer box (sequentially tapping is obligatory for mobile devices).
• Correct choices are signaled by boxes matching appearance and a border around the answer. Incorrect answers elicit a Sorry Mismatch popup.
• To conserve time, skip answers when you are certain that you know them.