Fed Chair Powell Says Trying To Manage Our Way Through The Tension Between Two Goals But This Is Not Stagflation; We Hope Gas Price Increase Is Not For A Long Period; We Don't Know How Big Effects On Gas Prices, Food Will Be; Don't Want To Speculate; We Will Learn A Lot Before Next Meeting; What Happens In Middle East Will Be A Big Factor; Did Talk About Alternative Scenarios, But It's Very Uncertain; U.S. Economy Has Been Strong Through A Whole Bunch Of Challenges