Gas prices continue to surge in the U.S. January 21, 2012- A recent survey shows that the average price of a gallon of gasoline increased nearly 3.5 cents to $3.39 in the United States. The increase covers the period between January 6 and January 20 and is based on the prices of over 2,500 filling stations throughout the country. The current average price is 28 cents above the price from a year ago at this same time. Survey officials have said gasoline retailers have increased the prices as they...