A.空格鍵B.退格鍵C.回車鍵D.向下鍵
A.DEL鍵B.INSERT鍵C.空格鍵D.退格鍵
A.打開NUMLOCK開關(guān)B.打開CAPS LOCK開關(guān)C.打開SCROLL LOCK開關(guān)D.按INSERT鍵