Rivers flow downhill because of gravity are large bodies of contained water usually end in mountainous areas are usually made of saltwater

Rivers flow from high areas to low areas, until it empties into a larger body of water, like a lake, a larger river, or the ocean.

Hence, the correct answer is A. flow downhill because of gravity.

shanghai

explanation:

after fierce fighting, the chinese armies were driven out of the shanghai area by the middle of november 1937. nanking (nanjing), the nationalist capital, fell in mid-december 1937, and the liquidation of that city and its inhabitants became known as the nanjing massacre.

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