4.Air Travel [00:01.46]4、航空之旅 [00:02.93](1)Buying Tickets and Making Reservations [00:05.41](1)购买机票和订位 [00:07.89]Model Dialogs [00:09.04]标准对话 [00:10.19]Dialog 1 Reserving Two Seats to New York [00:12.75]对话1 预订两个到纽约的座位...