1. física   psychology   geology   physics   astronomy   Hint Half-n-half Clue   2. zoología   geometry   geography   zoology   trigonometry   Half-n-half Clue   3. trigonometría   history   chemistry   geometry   trigonometry   Half-n-half Clue   4. álgebra   calculus   botany   geometry   algebra   Half-n-half Clue   5. astronomía   astronomy   algebra   botany   geology   Half-n-half Clue   6. historia   history   geometry   geography   physics   Half-n-half Clue   7. biología   philosophy   biology   geology   astronomy   Half-n-half Clue