The U.S. economy grew at an annual pace of 3.5% in the third quarter, according to a report from the Commerce Department released Thursday. The report signaled a change from four previous quarters of economic contraction. "This welcome milestone is just another step, and we still have a long road to travel until the economy is fully recovered," said Christina Romer, Obama administration chief economist. "It will take sustained, robust ... growth to bring the unemployment rate down substantially. Such a decline in unemployment is, of course, what we are all working to achieve."