According to the passage, in operating airlines it is essential to     .(  )

• A、keep in mind the need. of the executives only
• B、satisfy the need of the low fare passengers at the expense of the executives
• C、try to attract as many passengers as possible by reducing fares
• D、cater to the need of passengers setting at both ends of the jets

A. It goes like this,"A man without a smiling face must not open a shop.”

B. As luck would have it ,she sat down next t a gentleman who was more than a little distraught about the long wait for service.

C. Just what you and I would do,of course ;the smiled back at the baby.

D. No one was talking to anyone else, and all were probably thinking of a dozen other things they would rather be doing than“wasting time" sitting in that office.

E. Your smile brightens the lives of all who see it.

F. So, naturally.we are glad to see them.

Which of the following is a bad habit of the executive passengers that frustrates the airlines?(  )

• A、They do not book their seats in advance.
• B、They do not sit on the seats they are supposed to take.
• C、They do not travel on the flight they have booked.
• D、They do not pay in advance for the seats they book.