An airline passenger is planning a trip that involves three connecting flights that leave from Airports A, B, and C, respectively. The first flight leaves Airport A every hour，beginning at 8:00 a.m., and arrives at Airport B 
hours later. The second flight leaves Airport B every 20 minutes, beginning at 8:00 a.m., and arrives at Airport C 
hours later. The third flight leaves Airport C every hour, beginning at 8.45 a.m. What is the least total amount of time the passenger must spend between flights if all flights keep to their schedules ？（）
A.25 min
B.1 hr 5 min
C.1 hr 15 min
D.2 hr 20 min
E.3 hr 40 min
参考答案：B
解析：
要使在航班之间花的时间最少，则这些乘客应尽可能地赶上早一点的航班。设乘客上午8点从机场A出发，则于10点30分到达机场B，此时乘客只能乘10点40从B飞往C的航班，并于11点50后才能到达机场C，此时机场C的11点45分的航班刚开走5分钟，所以不得不等下一班，即55分钟以后的哪一班。综上所述，乘客在航班之间所花的时间应为10+55=65分钟。
