1.b> (); ; to travel (around) the world ; ; I always travel economy class - ;
2.b> (); ; ; in theory, nothing can travel faster than light , ; the sound travelled for miles i> ;
3.b> .i> () / ; ; this car can really travel ; ;
4.b> .i> (), (i>);
5.b> .i> 1) (), , ;
2) (), ; 3) / ();
4) ().