In 2012, Ben Bernanke said that Fed policy had raised real GDP by almost 3 percent. Mr. Bernanke believes that the Fed's policy of keeping the federal funds rate ________ had resulted in an increase in ________.
【简答题】He was so pleased with all ______ we had done for him _____ he wrote us a letter to praise us for it. A. what what B. what that C. that what D. that that