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