1. tian wen   history   astronomy   biology   trigonometry   Hint Half-n-half Clue   2. zhi wu xue   botany   trigonometry   geology   zoology   Half-n-half Clue   3. [hua;hua] xue   geology   chemistry   algebra   physics   Half-n-half Clue   4. [de;di] zhi   geology   geometry   algebra   psychology   Half-n-half Clue   5. xin li xue   psychology   botany   zoology   calculus   Half-n-half Clue   6. [ji;ji] [he;he]   algebra   geography   geometry   astronomy   Half-n-half Clue   7. wei ji [fen;fen]   philosophy   calculus   geometry   algebra   Half-n-half Clue