Билет 1.
The United States of America is the world's third largest country with an area of 9.6 million square kilometers, the population — over 300 million people (2007). Most of the country is in the central part of North America. It is bordered by Canada on the north and Mexico on the south, the Atlantic Ocean to the east and the Pacific Ocean to the west.
Due to its geographical position and administrative division the United States is one of the few fragmented countries in the world. Of the fifty states of the country forty-eight states are conterminous, or enclosed within one common boundary. The other two states, Alaska and Hawaii, are located apart from the rest of the country. Alaska is located in the far northwestern part of North America, bordering western Canada. Hawaii is in the Pacific Ocean to the south and west of mainland North America. The United States occupies a favourable geographical position. The Atlantic Ocean is of great importance for the country's sea communications with Europe, Africa and South America. The sea routes to Asia and Australia pass over the Pacific Ocean. The sea route through the Panama Canal, which connects the two oceans, runs over the Gulf of Mexico and the Caribbean Sea.
The physical geography of the United States is as varied as that of any other country in the world. There are huge forests, large areas of flat, grassy plains, and deserts. An average elevation of about 762 meters masks some great variations. These variations range from a low of 86 meters below sea level in California to a high of over 6,000 meters above sea level in Alaska.
The people of the United States are descended from many, many different groups of people from around the world. It is a country of immigrants. The first inhabitants came from Asia, crossing the Bering Strait into Alaska during the last Ice Age. Almost 40,000 years later, Spanish adventurers entered what is now the southwestern United States by way of Mexico. From that time, migrations have continued — Europeans, Africans, Asians, and other people from the Americas entering the country to live and work, adding their cultures to that of the nation.
The United States is spread over a huge area of the Western Hemisphere. For example, the total distance between the most eastern Florida Key and most western island of Hawaii is 9,418 kilometers. The conterminous United States stretches some 4,664 kilometers from Maine in the east to California in the west. From the northern border of North Dakota to the southern border of Texas, it is 2,585 kilometers.
It is little wonder that within a country so large there can be found so many different landscapes.
The country can be divided from the point of view of physical geography into nine regions. These are: (1) the Coastal plains, (2) the Appalachian Highlands, (3) the Interior Plains, (4) the Interior Highlands, (5) the Rocky Mountains, (6) the Intermontane Plateaus and Basins, (7) the Pacific Coastal Ranges, (8) Alaska, and (9) Hawaii.
Билет 2
The physical geography of the United States is as varied as that of any other country in the world
The Coastal Plains
A lowland area sweeps from Massachusetts to Texas along the coasts of the Atlantic Ocean and the Gulf of Mexico. This coastal plain, which extends for more than3,219 kilometers is divided into two parts — the Atlantic Coastal Plain and the Gulf Coastal Plain. The Atlantic Plain follows the coastline of the Atlantic Ocean south from Cape Cod in Massachusetts to the Florida Peninsula. The coastline is irregular. Many natural harbours have been created. Some of the more important ones are Massachusetts Bay, New York Bay, Delaware Bay, Chesapeake Bay, and Long Island Sound.
The Gulf Plain is a much wider band of flat land and gently rolling hills. It varies in width from 241 kilometers to about 966 kilometers. At one point, the plain extends far inland to where the Ohio River flows into the Mississippi River. The Mississippi, the longest river in North America, empties into the Gulf of Mexico in Southern Louisiana. There it has made a huge delta. This part of the Gulf Coastal Plain is made up of marshes and bayous — a word used to describe the many small, marshy creeks and rivers that flow through the delta area.
The Appalachian Highlands
Just west of the Atlantic Coastal Plain is the Appalachian Highlands. This region takes its name from the Appalachian Mountains. The highlands stretch about 1,931 kilometers in the United States from northern Maine to central Alabama. They lie in a northeast to southwest direction. In the highlands is the highest peak in the eastern United States — Mount Mitchell in western North Carolina. It rises 2,037 meters above sea level.
The eastern edge of the highlands is known as the Piedmont. This low plateau varies in altitude from 152 to 305 meters above sea level. West of the Piedmont are the Appalachian Mountains. They are nearly parallel with the Atlantic coastline.
The Interior Plains
A huge "plain region" covers the middle of the United States between the Appalachian Mountains and the Rockies. The region is divided into Central Plains the Great Plains. The Central Plains include lowland parts of central and western Kentucky and Tennessee, the Great Lakes area, and the upper Mississippi and lower Ohio and Missouri river basins. West of the river basins is the area of the Great Plains. Many long rivers flow eastward from the Great Plains, emptying into the Mississippi.
The Interior Highlands
Two separate highlands regions rise above the plains in the central United States. These are the Superior Highlands and the Ozark Plateau.
Located around Lake Superior, in the northern parts of Minnesota, Wisconsin, and Michigan, the Superior Highlands are actually a part of the Canadian Shield. Coniferous forests cover rocky plateaus. There are many lakes among the hills. The Ozark Plateau is located between the Missouri and Arkansas rivers west of the Mississippi River. The land is gently rolling in places with some rugged mountains in other places.
The Rocky Mountains
West of the Great Plains is the Rocky Mountain region. The Rocky Mountains extend from Canada south to New Mexico and Western Texas. The region occupies an area over 1,600 kilometers long, it varies in width between 200 to 600 kilometers.
The Rockies stretch from north to south. The Rocky Mountains are much more rugged and much higher than the Appalachians. Many peaks are over 3,658 meters high. Plants are greatly affected by altitude. Mountain tops not covered by snow are capped by tundra grasses and mosses.
Intermontane Plateaus
West of the Rocky Mountains lies an area of intermontane plateaus and basins. The term intermontane means "between mountains". The region lies between the Rocky Mountains and mountain ranges along the Pacific coast.
The intermontane area is long and broad, stretching from Washington to the border with Mexico. The mountains block rain, and as a result, the lowland basins are dry. Some of the most impressive landscapes in the country are found in the region. The best known is the Grand Canyon.
The Pacific Coastal Ranges
The most western of the physical regions of the conterminous United States is made up of the Pacific coast mountain ranges. Like the Rockies, they extend from Canada in the north to the border with Mexico in the south. The area is about 322 kilometers wide from east to west. It has some of the highest mountains as well as some of the richest farmland in the United States.
The interior range includes the Cascade Mountains in Washington and Oregon and the Sierra Nevada in California. Within the Sierra Nevada is Mount Whitney at 4,418 meters. Mount Rainier at 4,392 meters above sea level, is in the Cascade Range. Also in the Cascades are active volcanic peaks. Mount Helens erupted several times in recent years. Closer to the Pacific coast is a second range of mountains stretching from Washington to California.
Climate
The United States has areas of all five major climate groups.
Southern Florida has a tropical moist climate. Even in the coldest month of January, temperatures average above 21 degrees centigrade. The area has a growing season that lasts all year long.
North of the Ohio River and east of the Great Plains, there is a moist, cold winter climate. South of the Great Lakes, summers are hot and winters have at least one month of average high temperatures below 0 degree centigrate. East and West of the Great Lakes, summers are cooler and winters are longer.
Most of the Great Plains is under a semiarid climate. Rainfall averages only 20 to 51 centimeters a year. The Rocky Mountains block moisture from the west. Summers are very hot and winters are very cold on the plains. The range of temperatures is greater here than anywhere else in the country.
From the Rocky Mountains to the Pacific Coast, there are several small areas of similar climate broken up by the mountains. The highest parts of the Rockies are cold all year.
Basins in the intermontane region have a generally dry climate. This climate is found in parts of Nevada, Arizona, and New Mexico as well as in western Texas and southeastern California. Summers are generally hot with cold winters.
The Pacific Coast is under mostly moist mild winter climates of two kinds. The coastal mountains of northern California, Oregon, and Washington cause warm winds blowing in from the Pacific to dump their moisture over these three states. These lowland coastal areas have a midlatitude marine climate.
In central and southern California, there is a Mediterranean climate. Summers are dry and winters are cool and rainy.
The climate of Alaska is generally cold over the whole state. The Yukon River valley has a moist, cold winter climate of the subarctic variety. Along the southern coast of Alaska, temperatures are milder than in the Yukon Valley. North of the Brooks Range is the only area of polar climate in the United States.
The climate of Hawaii is tropical and moist. It receives short periods of rain throughout the year. There are, however, small variations. Some areas near the coast are drier while highlands are very wet. Mt. Waialeale, on the island of Kauai, is one of the wettest spots in the world.
Rivers and Lakes
The Mississippi River, along with its tributary, the Missouri, is one of the world's longest rivers. It flows from the Rocky Mountains for nearly 6,437 kilometers to the Gulf of Mexico. One of its folk names is "father of waters. The Ohio River is another major tributary of the Mississippi together with the Arkansas River and the Red River.
Like the Mississippi, the many shorter rivers that rise east of the Appalachian Mountains empty into the Atlantic Ocean. Among them are the Hudson River, the Delaware and the Potomac.
Three great river systems drain the region west of the Rocky Mountains. They empty into the Pacific Ocean. In the north, the Columbia River and its chief tributary, the Snake River, which drains part of Idaho, Washington and Oregon. The Sacramento and its main tributary, the San Joaquin, drain much of central and northern California. The Colorado River and its many branches drain much of southwestern United States. These three river systems have great value as sources for irrigation and hydroelectric power
The Rio Grande, about 3,200 kilometers long, forms a natural boundary between Mexico and the United States and is an important source of irrigation projects to the benefit of both countries.
The Yukon River in the north rises in the Canadian Rockies flows westward across Alaska and empties into the Bering Sea.
North America has more lakes by far than any other continent. The largest of these are the Great Lakes. They are the greatest collection of fresh water lakes in the world. Their total area is 245 thousand square kilometers. Lakes Superior, Huron, Erie, and Ontario form a natural border between northeastern United States and Canada. Only Lake Michigan lies entirely inside the United States. Lake Superior is the largest of the Great Lakes. It is about 563 kilometers long and 257 kilometers wide. The Great Lakes together with the Between LakeErie and Lake Ontario, on the Niagara River, which connects the two lakes, are the Niagara Falls, one of the natural wonders of the world, where the waters of the Niagara River precipitate from the height of 50 meters.
Another large group of lakes lies west of the Rockies. The most famous of these lakes are the Great Salt Lake, in Utah, and the Salton Sea lies about 80 meters below sea level in Southern California.
Mineral resources.
In resources of coal and natural gas, tungsten and molybdenum, lead and phosphorus the United States holds the first place in the world. In resources of copper, zinc and sulphur - the second. In resources of gold, silver, uranium, mercury and asbestos - the third. The United States is rich in oil, iron ore, various metallic ores. At the same time the country lacks a sufficient supply of some of the minerals required for modern industries. These must be imported into the United States. They include tin, nickel, manganese, chrome, cobalt, industrial diamonds.
The principal deposits of high-grade coals are concentrated in the eastern part of the country. The main producing areas are in the Appalachian region. Some other less important coal basins are to be found in the middle reaches of the Mississippi, in the north of the Great Plains and in the Rocky Mountains.
The chief oil-bearing area is in the southern part of the Interior Plains and the Gulf Coastal Plain. Other important oil fields are situated in the Pacific southwest (California) and the Rocky Mountains (Wyoming). Extensive oil-bearing areas have been discovered in the northern part of the Great Plains. Alaska is rich in oil and its resources are also tapped. Closely connected with oilfields are the vast deposits of natural gas (8 trillion cubic metres). However, the home resources of oil are insufficient, therefore the country is a major importer of oil from different countries of the world.
The chief deposits of iron ore are concentrated in the the region of Lake Superior. There are some deposits of iron ore in the south of the Appalachians, Birmingham, but the ores of this region are of a poorer quality, having a lower iron content.
Pittsburg, in the heart of coal-fields, was the first of the great steel cities, because it was cheaper to bring the ore to the coal than the coal to the ore. Today, the Pittsburgh area still produces about one-fifth of the nation's steel, and also supplies coal to the other great steelmaking centres - Chicago, Detroit, Cleveland, Buffalo.
Large deposits of non-ferrous metals are to be found mostly on the territory to the west of the Mississippi River - zinc, copper, lead and others. Principal resources of such metals as gold, silver and rare elements are in the Cordilleras. The main deposits of uranium are in New Mexico. In the total resources of uranium die United States is after the South African Republic and Canada.
As a whole, the United States has considerable resources of mineral raw materials for the development of industry. It is self-sufficient in coal, copper, lead, phosphate, molybdenum and some others.
In terms of costs oil, coal, natural gas, uranium consitute nearly 89 per cent of the total output of the extracting industry of the United States. Iron ore and copper constitute three-fourths of the cost of all the extracted metals.