(Слайд 6) 4. The Face of the Land

The framework of America is built around a huge interior lowland that has yielded some of the country's greatest agricultural and mineral wealth. It contains a large portion of its population and is the heart of what politicians like to call “middle America”. The region is drained by the Mississippi River and its great tributaries, one of the largest navigable river systems of the world. The Mississippi is the traditional dividing line between “East” and “West”. To east and west, the land rises to mountain ranges that flank the lowland to either side and separate in from the Atlantic and Pacific Oceans.

The Mississippi is one of the world's great continental rivers. It flows some 3,970 miles from its northern sources in the Rocky Mountains to the Gulf of Mexico, making it one of the world's longest waterways. The Missouri is its chief western branch. Where the Missouri pours into the Mississippi from the west, it colors the river deep brown with small pieces of soil. Farther downstream where the clear waters of the principal eastern tributary, the Ohio, join the Mississippi, evidence of the difference between the dry west and rainy east becomes apparent. For miles, the waters of the two rivers flow on side by side, without mixing. Those from the west are brown because they wash away the soil in areas of sparse vegetation. The waters from the east are clear and blue. They come from hills and valleys where plentiful forest and plant cover has kept the soil from being washed away.

Like the Mississippi, all the rivers east of the Rockies finally reach the Atlantic; all the waters to the west ultimately flow into the Pacific.

The two great rivers of the Pacific side are the Colorado in the south, and the Columbia, which originates in Canada and drains the north The Columbia flows with quiet dignity.

The Rio Grande, about 1,990 miles long, is the foremost river of the Southwest. It forms a natural boundary between Mexico and the United States, which together have built irrigation and flood control projects of mutual benefit.

North of the Central Lowland, extending for almost 994 miles, are the five Great Lakes which the United States shares with Canada.

(Слайд 7) 5. Climate and weather

On arriving in America Europeans had to learn to cope with the variety of unfamiliar climates and vegetation. European climatic experience was not a very useful guide for survival in America. That was especially true in the subtropical South and the arid West, regions that provided unexpected opportunities but also posed obstacles for which there were no obvious analogies in the Old World.

Europeans expected America to be much the same, as America faced the Atlantic, just like Europe. The truth was quite different. America’s western air comes not from the ocean, as in Europe, but from the continental interior which is extremely cold in the winter and oven like in the summer.

The northernmost zone, adjacent to the Canadian border, is region of northern forest that stretches from Maine across northern New England and the upper Great Lakes. Here the growing season very short, and the winters are long and fiercely cold. For farmers has always been miserable country.

Southward the temperature moderates. The growing season longer, winters are milder, and summers are hot. Because America, summers were considerably hotter and longer than in Europe. American crops often yielded a larger harvest.

Still farther southward one crosses an invisible but crucial line called the Mason-Dixon Line. The central features of Southern climate are hot humid summers and a long growing season. The climate is good for a variety of valuable subtropical crops, such as indigo, rice and cotton. Monopoly of the American South came to an end in the century as a result of competition from Indian cotton.

The climate of the Central Basin is rather moderate. Moist and dry years alternate. Intensive plowing exposed the cultivated soil to the storms.

Further west, in the semi-arid region of short grass where farms and cattle ranches begin. In years when rain is plentiful, the prairie grasses grow well and the herds of cattle grow fat. But during frequent droughts large herds of cattle suffer and may even die. The first farmers and ranchers had to learn climatic laws the hard way.

The only substantial humid region in the western United States is wedged into a narrow strip between the Pacific coast and the Sierra-Cascade ridge line. Unlike the East, with its continental extremes of summer and winter temperature, West Coast temperatures are moderated all year long by westerly winds from the ocean so that the entire coast from Canada to Mexico enjoys cool summers and mild winters.

On the West Coast, winter is the rainiest time everywhere, and summers almost everywhere are very dry. Under natural conditions brushfires are part of the natural ecological cycle, and periodic burning keep brush down and grasslands open. But when fires get started in California cities – and it is impossible to prevent them all – they can be devastating.

Despite drought and fire, Americans have found California's Mediterranean climatic zone a particularly alluring place. Near the coast summers are cool and pleasant, and even the mild rainy winter is often not very rainy, except in the far north. The combination has attracted both tourists and permanent residents from harsher climates in the North and East.

So the large variety of geographic and climatic environments in America guaranteed that people in America would find both opportunities and challenges.