Yellen says no clear timeline on when oil, dollar will stabilize

WASHINGTON (Reuters) - Federal Reserve Chair Janet Yellen said on Thursday that it is still uncertain when energy prices and the dollar will stabilize. "It's hard to predict exactly when that will be and there can be and have been surprises," Yellen told a committee of lawmakers in Congress. Low oil prices and the strong dollar have both put downward pressure on inflation, which remains well below the U.S. central bank's two-percent target rate. (Reporting by Lindsay Dunsmuir)