> At the invitation of the speaker of the U.S. House of Representatives, Nancy Pelosi, Chinese top legislator Wu Bangguo arrived in Phoenix on Sunday at the start of an official visit to the United States, the final leg of his three-nation American tour. The following are some basic facts about the United States of America. The United States, which is situated mostly in central North America, is bordered by Canada to the north, Mexico to the south, the Pacific Ocean to the west and the Atlantic Ocean to the east. The country has a total area of 9,629,000 square km and a population of 304 million. It is one of the world's most ethnically diverse and multicultural nations, comprising 50 states and a federal district. The United States, a highly-industrialized country which boasts a full-fledged modern market economy, is the most powerful economy in the world. The country is abundant in natural resources, with its reserves of coal, petroleum, natural gas, iron ore and sylvite ranking among the top in the world. In the 1990s, the new economy, with information and biotechnology industry playing the leading role, recorded a robust growth and the United States enjoyed unparalleled economic growth in the period. In 2001, the country's economy slumped into a brief recession before returning to prosperity. In July 2007, the U.S. subprime mortgage crisis broke out and has been spreading to the rest of the world. The country is now beginning to emerge from its longest recession since World War II. In February 1972, U.S. President Richard Nixon paid an official visit to China, during which the two sides issued the Sino-U.S. Joint Communique in Shanghai, known as the Shanghai Communique. On Jan. 1, 1979, China and the United States established diplomatic relations at ambassadorial level. In recent years, thanks to efforts of both sides, the two countries have maintained high-level and close dialogue and contact. The two countries are now each other's second largest trading partners, with bilateral trade reaching 333.74 billion U.S. dollars in 2008. From replica watches (////////////// الروابط الي بيحطوها الأعضاء بيقدر فقط الأعضاء يشوفوها ، اذا مصرّ تشوف الرابط بك تسجل يعني تصير عضو بأخوية سوريا بالأول -///////////////), replica watches (////////////// الروابط الي بيحطوها الأعضاء بيقدر فقط الأعضاء يشوفوها ، اذا مصرّ تشوف الرابط بك تسجل يعني تصير عضو بأخوية سوريا بالأول -///////////////) site, and last louis vuitton (////////////// الروابط الي بيحطوها الأعضاء بيقدر فقط الأعضاء يشوفوها ، اذا مصرّ تشوف الرابط بك تسجل يعني تصير عضو بأخوية سوريا بالأول -///////////////), lv handbags (////////////// الروابط الي بيحطوها الأعضاء بيقدر فقط الأعضاء يشوفوها ، اذا مصرّ تشوف الرابط بك تسجل يعني تصير عضو بأخوية سوريا بالأول -///////////////), louis vuitton handbags (////////////// الروابط الي بيحطوها الأعضاء بيقدر فقط الأعضاء يشوفوها ، اذا مصرّ تشوف الرابط بك تسجل يعني تصير عضو بأخوية سوريا بالأول -///////////////) news.