I have a rule for travel: Never carry a map. I prefer to ask for directions. Foreign visitors are often puzzled in Japan because most streets there don't have names. In Japan, people use  _ in their directions instead of street names. For example, the Japanese will say to travelers, "Go straight down to the corner. Turn left at the big hotel and go past a fruit market. The post office is across from the bus stop."      In the countryside of the American Midwest, usually there are not many landmarks. There are no mountains, so the land is very flat . In many places there are no towns or buildings within miles. Instead of landmarks, people will tell you directions and distance. In Kansas or Iowa, for example, people will say, "Go north two miles. Turn east, and then go another mile." People in Los Angeles, California, have no idea of distance on the map: They measure distance by means of time, not miles. "How far away is the post office?" you ask. "Oh," they answer, "It's about five minutes from here." You say, "Yes, but how many miles away is it?" They don't know.      People in Greece sometimes do not even try to give directions because visitors seldom understand the Greek language. Instead of giving you the direction, a Greek will often say, "Follow me." Then he'll lead you through the streets of the city to the post office.       Sometimes a person doesn't know the answer to your question. What happens in this situation? A New Yorker might say, "Sorry, I have no idea." But in Yucatan, Mexico, no one answers, "I don't know." People in Yucatan think that "I don't know" is impolite. They usually give an answer, often a wrong one. A visitor can get very, very lost in Yucatan! One thing will help you everywhere -- in Japan, in the United States, in Greece, in Mexico, or in any other place. You might not understand a person's words, but maybe you can understand his body language. He or she will usually turn and then point in the correct direction. Go in that direction, and you may find the post office! The passage mainly tells us that   _  .
never carry a map for travel there are not many landmarks in the American Midwest there are different ways to give directions in different parts of the world New Yorkers often say, "I have no idea," but people in Yucatan, Mexico, never say this.