Charlie said, "I don’t know what Fred is doing". a. He said that he doesn’t know7/20Charlie said, "I don’t know what Fred is doing".He said that he doesn’t know what Fred is doing.He said that he didn’t know what Fred is doing.He said that he doesn’t know what Fred was doing.He said that he didn’t know what Fred was doing.Giải thíchChọn đáp án D