Air travel is an everyday experience these days because it's so fast. But long-distance flying can be very tiring and the traveller begins to feel his brain is in one country while his body is still in another. In short, he hardly knows where he is. Tiredness after a long flight becomes stronger when we fly from east to west because we cross time zones（时区）. Doctors says that air travellers should go straight to bed on arrival after crossing a number of time zones. They shouldn't work without rest. However, airline pilots don't need to do it. In fact, they often live by their own watches, paying no attention to local time. They can even have breakfast at midnight if necessary. Businessmen, however, are not so lucky. After a long journey, they must either go straight to an important meeting or to meet their boss to give a report. Even so, there are still a lot of businessmen travelling by air.

A．The traveller becomes foolish.

B．The traveller feels uncomfortable.

C．The traveller doesn't know where he is.

A．go to work without wasting time

B．take exercises to relax

C．go to bed and have a good rest

(4) Pilots can hardly be affected by frequent（频繁的）flying because they ________.

A．are especially strong men

B．live by their own timetable

C．like flying

A．going back home and having a good rest

B．reporting to their boss

C．going to a meeting