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