The airline offers special services for travelers in first and second class.航空公司为一等舱和二等舱的旅客提供特殊服务。To save money, we traveled second-class.为了省钱，我们乘坐二等舱旅行。He bought a second-class ticket.他买了一张二等舱的票。He was travelling second class.他乘二等舱旅行。She always travels second-class.她外出旅行总是坐二等舱。