1. 代数   chemistry   geography   algebra   geology   Hint Half-n-half Clue   2. 动物学   algebra   chemistry   calculus   zoology   Half-n-half Clue   3. 地质   calculus   chemistry   zoology   geology   Half-n-half Clue   4. 生物   geometry   biology   trigonometry   physics   Half-n-half Clue   5. 三角学   biology   geography   geometry   trigonometry   Half-n-half Clue   6. 植物学   chemistry   psychology   geometry   botany   Half-n-half Clue   7. 天文   astronomy   zoology   geography   physics   Half-n-half Clue