What is the main condition needed for a river to develop?

How much does a sea wall coast? How do people use forest in the Atlantic coast and Appalachian states? Why can animals live in a desert without dying a human bean can not live as long? When was Happyland Amusement Park created? Ponds and lakes are sources of what? When was Long Beach Aftershock created? How does the south beach diet affect your body? How long does it take to decorate Christmas tree in Times Square? Can you swim IN RIVER if you have belly botton pierced? Where can you find where the oasis is located at? What did the workers live while building the hoover dam? When was Peacock's Lock Viaduct created? Who claimed the huge area from the great lakes to the gulf of Mexico for France? How can you measure the speed of ocean waves? Where is the Baker Family Museum in Caldwell Ohio located? Why does the ganges river remain important to India? How did people feel about Abigail Adams? Crater Lake in Oregon is an example of what? Where is the wall made by king zulkarnain? What type of movie is Night at the Museum?