1. 微积分   chemistry   history   botany   calculus   Hint Half-n-half Clue   2. 天文   astronomy   physics   algebra   geology   Half-n-half Clue   3. 地质   geology   psychology   algebra   trigonometry   Half-n-half Clue   4. 几何   geometry   calculus   physics   algebra   Half-n-half Clue   5. 历史   calculus   geometry   algebra   history   Half-n-half Clue   6. 哲学   chemistry   geometry   philosophy   geography   Half-n-half Clue   7. 化学   zoology   geometry   psychology   chemistry   Half-n-half Clue