Keep it up. U.S. stocks logged their best week of the year, closing Friday with the Dow Jones up 93 points and the NASDAQ up 1 percent. The drive this week came amid uncertainty in Europe, and speculation that Spain would ask for assistance for its debt-laden banks on Saturday. “There’s a lot of uncertainty out there,” said Bernard Kavanagh, vice president of a St. Louis brokerage house. “I’m surprised we didn’t see more selling given the strong week we’ve had.” International action by major national central banks, including those in China and Europe, helped support the strong showing for the markets this week, and Federal Reserve chairman Ben Bernanke told reporters Wednesday that he too is prepared to act to help bolster the U.S. economy.