Answer:
The US liquid gallon is a unit of fluid volume equal to four quarts, eight pints, or sixteen cups.
Europe is not a typically dry place (unlike for exampe Mesopotamia) so it does not need rivers for irrigation.
Instead, rivers are needed more for transport - they have served as a means of communication and for the exchange of goods.
For example, Danube allowed a big-scale trade between the cities lying on it: Vienna, Budapest and Bratislava.
The answer is A.it forms on the earths surface
Most of the world's known oil reserves are located near the Persian Gulf
