Travelers 【T1】_________ into two categories：those who make lists and those who do not. Some people prefer to plan the course of

Travelers fall into two categories: those who make lists and those who do not. Some people prefer to plan the course of their trip to the finest detail. For others the joy of a trip is its spontaneity.
       Neither approach works perfectly in South America. It is an area that requires considerable preparation: internal flights often run only once or twice a week, and an advance booking can mean the difference between continuing to a new city and waiting several days for another flight.