Canada lies in the north part of North America. It stretches (延伸) from the Atlantic Ocean to the Pacific Ocean. To the north is the Arctic Ocean. Canada is the world's second largest country. It takes up most of the northern part of the North American continent and covers about 6.6 percent of the total land of the earth. Although large in area, Canada has a population of only a little over 29 million. There are only about six persons per square mile. Most of Canada is thinly inhabited(定居). Most of northern Canada is wilderness, forest of frozen Arctic wasteland. Nearly 80% of Canadians live in large cities near the border with the United States. 60% of the population is concentrated (集中) between Quebec City and the western end of Lake Ontario. Canada's largest city, Toronto, has a population of over 3.4 mil- lion, and the third largest city is Vancouver which has a population of over 1.3 million. Most Canadian cities are much smaller. More than 44 percent of the population is British in origin(血统), and 28 percent is French in origin. Cultural and political differences between these two major groups have played an important. part in the country's history. Other European groups in Canada include Germans, Ukrainians, Italians, Dutch, Scandinavians, Hungarians, Russians and Poles. The non-white population, which is made up of Eskimos, Indians, Asians, and black, make up about 4 percent of the population. What does the text mainly discuss on Canada?