  2
   ,        2;      .

:
-     <>,                  2.         .
-          2,        2,       .         . 
-          2,        2,    <Ctrl> + <2>  .         . 
-          2,       .
-          2,   <2>  .
-               ,       .          .    
-            2D  3D    <>   .               2D/3D  .   
-       <>    .