LANSING, Mich (WLMI)  Gas prices continue to fall.  The average price for a gallon of gas in the U.S. is  $3.48 a gallon.  That's 15 cents lower than two weeks ago and almost 50 cents below the highest price of the year, which was in place in early April.  The figures are from the Lundberg Survey.  Analyst Trilby Lundberg says uncertainty in Europe is causing a drop in crude oil prices.  According to GasBuddy.com--the average in the Lansing area is $3.52 a gallon.