People　can　see　someone　who　may　be　an　acquaintance　or　stranger　when　they　are　on　the　way,　or　at　a　bus　stop,　in　a　campus,　in　a　cinema,　in　a　scenic　zone　etc.　They　may　say　hello　to　the　acquaintance,　or　ask　somebody　where　the　toilet　or　the　nearest　gas　station　is.　People　may　chat　or　play　game　with　others　to　kill　time　when　they　are　waiting　at　a　station　or　an　airport,　or　in　a　couch.　People　can　see　some　shops,　such　as　clothes　store,　copy　shops,　or　snack　bar　etc.　people　may　enter　to　get　some　service,　such　as　to　copy　some　materials,　or　to　do　some　shopping.　They　may　hear　or　see　some　announcements,　such　as　the　mention　to　mute　the　mobile　phone　in　a　cinema,　or　the　arriving　time　and　the　name　of　the　next　station　of　the　train,　or　the　delayed　flight　notice　at　the　airport.　Of　course,　they　may　see　some　advertisement.　The　scenes　above　are　all　related　to　some　area　where　someone　moves　in.　For　example,　the　people　waiting　at　an　airport　may　want　to　look　for　someone　to　play　card　or　games　to　kill　time,　while　he　may　have　important　things　to　do　when　he　leaves　the　airport.　©　2012　Springer-Verlag　London　Limited.