When mobile phone has become one of the essential necessities in people's life,it offers us a sense of security and enables us to send or receive message at any time.It has been the primary tool for communication and sometimes overpasses the face-to-face communication.People make a call or send messages almost everywhere,in the subway,dining-hall or on the street.Mobile phone has become our bridge in life.If there were no mobile phones one day,what will happen to your life?