The vast expanse of the United States of America stretches from the heavily industrialized, metropolitan Atlantic seaboard across the rich flat farms of the central plains, over the Rocky Mountains to the fertile west coast, then halfway across the Pacific to the balmy (温和的) island-state of Hawaii. The American scene awes the viewer with both its variety and size. The continental United States (not counting outlying Alaska and Hawaii) measures, 4,500 kilometers from its Atlantic to Pacific coasts, 2,575 kilometers from Canada to Mexico. The entire nation (all 50 states) covers an area of 9 million square kilometers and has a population of 220 million people. The sparsely settled, far-northern state of Alaska is the largest of America’’s 50 states. It is more than two and a half times the size of Sichuan province. Texas, in the southern part of the country, is second in size. Texas is half the size of Alaska. A land of heavy forests (311 million hectares) and barren deserts, of high-peaked mountains and deep canyons, America also enjoys bountiful rivers and lakes. The broad Mississippi River system, famed in song and legend, meanders 6,400 kilometers from Canada to the Gulf of Mexico— the world’’s third longest river after the Nile and Amazon. A c in the north join the Mississippi to the five Great Lakes— the world’’s largest inland water transportation route and the biggest body of fresh water in the world. America’’s early settlers were attracted by the fertile land and varied climates it offered for farming. Today, with 121 million hectares under cultivation, American farmers plant spring wheat on the cold western plain; they raise corn and fine beef cattle in the central plains, and rice in the damp heat of Louisiana. Florida and California are famous for their citrus fruits and tropical avocados; the cool rainy northeastern states for apples, pears, berries and vegetables. America has long been known as a "melting pot," for it is a nation of immigrants from all over the world. Europe, the major source of immigrants, began sending colonists to America in the early 17th century. Tens of millions flooded to America’’s shores from Europe between 1880 and the First World War. The next largest group of Americans trace their ancestry to Africa, black people now constitute over 11 percent of the population. The melting pot has also absorbed nearly 600,000 Japanese, half a million Chinese and 340,000 Filipinos. Many live in Hawaii, more than two-thirds of whose people boast on Asian or Polynesian heritage. The visitors will be in awe of American landscape for its__________.