1.Book two tickets for me please.
2.Book four tickets to Shanghai tomorrow morning please.
3.I missed the plane,it left me with no choice but to change the ticket.
4.I missed the train,I could only change/refund the ticket or take the next train.
5.(1) The flight to Beijing took off just now.
(2) The flight to Beijing has taken off for one hour.
6.(1)The train to Shanghai just left.
(2) The train to Shanghai has left for 3 hours.
就用left就行了.