1. química   chemistry   geography   psychology   calculus   Hint Half-n-half Clue   2. psicología   history   philosophy   algebra   psychology   Half-n-half Clue   3. geografía   botany   geography   philosophy   psychology   Half-n-half Clue   4. cálculo   algebra   calculus   botany   geography   Half-n-half Clue   5. biología   chemistry   astronomy   biology   geography   Half-n-half Clue   6. zoología   chemistry   trigonometry   zoology   psychology   Half-n-half Clue   7. trigonometría   trigonometry   psychology   philosophy   history   Half-n-half Clue