I would like to make the example as China economy in order to analyze how the structure of an economy has changed in the 21st century.
To a variety of industries around the world is divided into three categories: primary industry, secondary industry and tertiary industry. Primary industry refers to the provision of production industries, including forestry, farming, aquaculture, animal husbandry and other natural objects as objects directly in the production sector. The second refers to industrial processing industries, the use of the basic means of production for processing to sale. Tertiary industry refers to all industries to provide services, such as the legal profession, the medical profession, wholesale trade, retail trade education.
According to China's geographical advantage, China has the absolute advantage to develop the primary industry. The early period of the china mainly develop 'the primary industry’. Western of the china has a dry climate and sparsely populated. Therefore early residents mainly nomadic, Inner Mongolia is China's largest grassland pastures and the Xinjiang after the second. And China's low-lying eastern and rainfall, which is the reason why agriculture is mainly eastern half of the land. Due to the humid climate so living in the plains and hilly areas of most residents farming mainly, the development of forestry in the mountains, the rivers, lakes and coastal areas along the fisheries.
However, for the sake of development of economic the china must make a choice to change their original industry to the secondary industry and tertiary industry. According the opportunity cost china need to make a choice between several mutually exclusive alternatives given limited resources. Faced with the growth of global agricultural science and technology, China has been as good as in the past, Agricultural selling more expensive than other European countries with poor quality, China has no absolute advantage already, so the development of