1. 杉木   cedar   chestnut   oak   pine   Hint Half-n-half Clue   2. 冷杉   beech   poplar   birch   fir   Half-n-half Clue   3. 白杨树   fir   birch   poplar   oak   Half-n-half Clue   4. 山毛榉   birch   beech   oak   maple   Half-n-half Clue   5. 榆木   oak   chestnut   elm   poplar   Half-n-half Clue   6. 槭树   cedar   beech   oak   maple   Half-n-half Clue   7. 橡木   maple   oak   poplar   birch   Half-n-half Clue