According to the article，some languages of American Indians are________.

保护世界文化遗产

Tourism was brought sharply into international focus at the end of the Second World War.Within a mere 20 years of the industry’s take-off, international tourism displayed nearly all the characteristics of its manufacturing counterpart—it was mass，standardized and rigidly packaged.By the mid-1970s，tourism was being produced along assembly-line principles，similar to the automobile industry, with tourists consuming travel and leisure services in a similar robot-like and routine manner.Understanding the evolution of mass tourism，and the factors that created it，are key to understanding the industry’s transformation.

Travel，whether for business or pleasure，requires arrangements.The traveler usually faces a variety of choices regarding transportation and accommodations;and if the trip is for pleasure，there are a variety of choices regarding destinations，attractions，and activities.The traveler may gather information on prices，value，schedules，characteristics of the destination，and available activities directly, investing a considerable amount of time on the Internet or possibly money on long-distance telephone calls to complete the trip arrangements.Alternatively, the traveler may use the services of a travel agency, obtaining these arrangements.

永久移民

旅游保险

国家级“旅游度假区”

签约国

心理承受力

需求不足

旅游业对经济的影响