1. 公共汽车   bus   airplane   truck, lorry   ship   Hint Half-n-half Clue   2. 直升机   helicopter   motorbike, motorcycle   truck, lorry   ship   Half-n-half Clue   3. 轮渡   taxi, cab   bus   ferry   truck, lorry   Half-n-half Clue   4. 小船   bus   car   boat   motorbike, motorcycle   Half-n-half Clue   5. 火车   bicycle   train   bus   car   Half-n-half Clue   6. 自行车   bicycle   helicopter   ship   motorbike, motorcycle   Half-n-half Clue   7. 汽车   ferry   boat   train   car   Half-n-half Clue