Traveling can be fun and easy. A vacation trip to another country is especially 【21】______ when the traveling conditions are good. Good traveling conditions 【22】______ a comfortable mode of transportation, knowledge of the 【23】______ language, familiarity 【24】______ the custom and habits of the people in the country, and pleasant traveling 【25】______ . All of us have had nice trips 【26】______ this. Most of us have also had trips that we would 【27】______ to forget. Many conditions can produce a bad 【28】______ experience. For example, if the four conditions 【29】______ above do not exist, we will probably have a bad experience, 【30】______ at best difficult 【31】______ . Students who travel to a 【32】______ country to study often have a difficult trip. They usually travel 【33】______ . They don't know the language of the new country 【34】______ . They often arrive in the new country 【35】______ a judge international airport. From the airport, they need to 【36】______ their way to their school. Maybe they need to 【37】______ airplanes, to take a bus, a train, or a taxi. They need to do ail this in a country 【38】______ everything is unfamiliar. Later, after the experience is 【39】______ , they can laugh. But at the 【40】______ , they feel terrible. 【21】