Charlie said, "I don’t know what Fred is doing"12/15Choose the best answer to complete these following sentences. Charlie 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 thíchĐáp án: D Dịch: Anh ấy nói rằng anh ấy đã không biết Fred đang làm gì.