The United States of America is the world's fourth largest country after Russia, Canada and China. There are 50 states in the country. 
   The USA borders on Canada in the north and Mexico in the south. 
The United States streches from the Pacific Ocean in the west to the Atlantic Ocean in the east.
  Long mountain chains run down the Pacific coast. There is Death Valey and the Grand Canyon in this part of the country. Farther east lie the Rocky Mountains and the Great Plains where the mighty Mississippi River flows. The Appalachians runs down the eastern part of the United States.