介绍美国概况 英语演讲稿

The United States of America (commonly referred to as the United States, the U.S., the USA, or America) is a federal constitutional republic comprising fifty states and a federal district. The country is situated mostly in central North America, where its forty-eight contiguous states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by Canada to the north and Mexico to the south. The state of Alaska is in the northwest of the continent, with Canada to its east and Russia to the west across the Bering Strait. The state of Hawaii is an archipelago in the mid-Pacific. The country also possesses several territories, or insular areas, scattered around the Caribbean and Pacific.

At 3.79 million square miles (9.83 million km²) and with about 305 million people, the United States is the third or fourth largest country by total area, and third largest by land area and by population. The United States is one of the world's most ethnically diverse and multicultural nations, the product of large-scale immigration from many countries. The U.S. economy is the largest national economy in the world, with an estimated 2008 gross domestic product (GDP) of US$14.3 trillion (23% of the world total based on nominal GDP and almost 21% at purchasing power parity).

The nation was founded by thirteen colonies of Great Britain located along the Atlantic seaboard. On July 4, 1776, they issued the Declaration of Independence, which proclaimed their independence from Great Britain and their formation of a cooperative union. The rebellious states defeated Great Britain in the American Revolutionary War, the first successful colonial war of independence. A federal convention adopted the current United States Constitution on September 17, 1787; its ratification the following year made the states part of a single republic with a strong central government. The Bill of Rights, comprising ten constitutional amendments guaranteeing many fundamental civil rights and freedoms, was ratified in 1791.

In the 19th century, the United States acquired land from France, Spain, the United Kingdom, Mexico, and Russia, and annexed the Republic of Texas and the Republic of Hawaii. Disputes between the agrarian South and industrial North over states' rights and the expansion of the institution of slavery provoked the American Civil War of the 1860s. The North's victory prevented a permanent split of the country and led to the end of legal slavery in the United States. By the 1870s, the national economy was the world's largest. The Spanish–American War and World War I confirmed the country's status as a military power. In 1945, the United States emerged from World War II as the first country with nuclear weapons, a permanent member of the United Nations Security Council, and a founding member of NATO. The end of the Cold War left the United States as the sole superpower. The country accounts for approximately 50% of global military spending and is a leading economic, political, and cultural force in the world.
这是维基百科关于美国的简介，稍微整理一下变成自己的语言，应该可以用。

The United States of America is a federal constitutional republic comprising fifty states and one federal district. The country is situated almost entirely in the western hemisphere: its forty-eight contiguous states and Washington, D.C., the capital district, lie in central North America between the Pacific and Atlantic Oceans, bordered by Canada to the north and Mexico to the south; the state of Alaska is in the northwest of the continent with Canada to its east, and the state of Hawaii is in the mid-Pacific. The United States also possesses fourteen territories, or insular areas, that are scattered around the Caribbean and Pacific.

At 3.79 million square miles (9.83 million km²) and with over 300 million people, the United States is the third or fourth largest country by total area, and third largest by land area and population. The United States is one of the world's most ethnically diverse nations, the product of large-scale immigration from many countries.[6] Its national economy is the largest in the world, with a nominal 2006 gross domestic product (GDP) of more than US$13 trillion.[3]

The nation was founded by thirteen colonies of Great Britain located along the Atlantic seaboard. Proclaiming themselves "states," they issued the Declaration of Independence on July 4, 1776. The rebellious states defeated Britain in the American Revolutionary War, the first successful colonial war of independence.[7] A federal convention adopted the current United States Constitution on September 17, 1787; its ratification the following year made the states part of a single republic. The Bill of Rights, comprising ten constitutional amendments, was ratified in 1791. In the nineteenth century, the United States acquired land from France, Spain, Mexico, and Russia, and annexed the Republic of Texas and the Republic of Hawaii. The American Civil War ended slavery in the United States and prevented a permanent split of the country. The Spanish-American War and World War I confirmed its status as a military power. In 1945, the United States emerged from World War II as the first country with nuclear weapons and a permanent member of the United Nations Security Council. The sole remaining superpower in the post–Cold War era, the United States is perceived by many as the dominant economic, political, cultural, and military force in the world.