1. álgebra   zoology   geometry   calculus   algebra   Hint Half-n-half Clue   2. cálculo   geology   geography   chemistry   calculus   Half-n-half Clue   3. historia   astronomy   history   trigonometry   psychology   Half-n-half Clue   4. geología   geology   trigonometry   calculus   geometry   Half-n-half Clue   5. botánica   calculus   astronomy   botany   algebra   Half-n-half Clue   6. filosofía   zoology   history   philosophy   biology   Half-n-half Clue   7. química   history   biology   chemistry   geometry   Half-n-half Clue