What is the Meaning of period covered?

The years of Mongol rule are characterized by? What is acid rain and what causes it? What damage did the japan earthquake do the the pacific ocean? How are streams diferennt than gullies? When is next barnehurst train to London bridge? How many parts are there on the Eiffel Tower? When was Tøjhus Museum created? How deep is lake Huron in meters? What is the current price per kilowatt hour from Hoover Dam? Which one among the following is responsible for the expansion of water in the ocean? How many haunted places are in Connecticut? What is the adult daily admission to Universal Studios? What event happend first endangered species act passed national forest service created Department of the Interior created national park serivce established? What are tourist types? What is about 700 miles west of lake balkhash is this major body water? What kind of animals live in tiga biome areas? Which oceans does the equartor cross? What is the phone number of the Dougherty Museum in Longmont Colorado? How many zoos are in California? If you sailed directly east from the US across the Atlantic ocean on which two continent could you land on?