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