单项选择题
A.三十分钟 B.四十分钟 C.二十分钟 D.五十分钟
A.I’ll check and come back to you soon B.Sorry，we don’t have C.Sorry，you do not have booked it
A.起飞前 B.登机时 C.餐饮服务前 D.细微服务时