Aircraft systems

2.3 Characteristics of international trade: Traditionally the large commercial areas of the world have been the European Union, the US and Japan. However, the emerging countries such as China have begun to play a key role in the international trade and economy. Different regions of the world specialize in the production of different goods: Developed countries (mainly North America, Japan and Europe) exported manufactured and highly-quality products, which provides high incomes. However, less developed countries contribute to international trade with raw materials, agricultural products and some basic manufactured goods, like textiles and craft products, which provides few incomes. Moreover, many poor countries owe money to foreign financial institutions (external debt), which is a serious problem for these countries. 3 Transport: is a fundamental activity of the tertiary sector. It is used to move people and goods. It reuqires two types of elements: Means of transport, which are the vehicles used for such transfer: automobile, train, plane, boat... Infrastructures, which are the elements necessary to operate the means of transport: roads and motorways for cars; railroads stations; airports for aircraft and seaports or fluvial ports for ships. The main systems of transport are road transport, rail transport, air transport and maritime transport. 4 Tourism: is all displacement of people to places that are outside their habitual residence for leisure reasons. It is important to a country´s economy because it helps to create and expand companies and services, creates jobs and it is also a major source of incomes. The development of tourism has positive and negative effects: positive effects: It is a large source of income for the host country. It boosts the economy and creates jobs. It simulates other economic sectors, especially construction, and leads to improved infrastructures and means of transport. It also promotes contact with other cultures and encourages the learning of languages. Negative effects: It leads to higher prices, promotes land speculation, enriches large companis and many of the jobs it creates are poorly paid. Tourism is seasonal, which causes temporal unemployment. It can also have serious environmental impacts, like intense construction and coastline alterations. It also generates waste, noise, pollution and increases water and energy consumption