A.The man's personal experience in military service.
B.The man's travel experience in Asia by traln.
C.The man's travel experience all these years.
D.The man's published collection of articles.
A.Train travel can help him know about people.
B.Train travel is an uncomfortable experience for him.
C.Train travel is better than plane travel because it saves money.
D.He doesn't care much about travel vehicles.
A.Most advertisements on TV are cheating consumers.
B.Watching TV costs us much money.
C.People spend too much time watching useless things.
D.Watching TV consumes too much energy.