The kites used by German U-boats in World War I for the military purpose were made of .

Human beings are curious about the world in which we live. We long to know what other places look like - - the people, their culture, the animals and the plants. Today, higher levels of education and the influence of television and other communications media have combined to create in us a much greater awareness of our entire world. We are now in a global economy and our industries may be globally competitive. We must think globally. Material prosperity in many developed countries, with higher standards of living, has made travel attainable for hundreds of millions of us. Although travel can be taken for many reasons, the most common are pleasure, business and study.

Tourists who wish to see as much of the countryside as possible may elect to take a coach tour staying at different places each night. 'The size and quality of the hotel used may be of secondary importance to the route and itinerary of the trip. Then there are others who wish to avoid the strains of one night stands, who will pick two or more resorts for their holiday. They may experiment with the hotel used at one (or all) of the destinations, Further, if the resort they wish to visit has limited accommodation facilities, the short-stay tourist might accept this, although for a longer one-resort holiday they might demand better quality and so choose a different resort. The support services in the packages will also be affected by the above considerations.

第三产业

以市场为导向的改革

收支平衡

无形产品

运载能力

资本投资

国民生产总值

消除紧张