First, I request you to add a meaningful topic for your essay when you open a new thread (type a meaningful topic in the "subject" field). It helps you earn good feed backs.
Nowadays, the emergence of telephone have significantly changed people's life, it makes life much easier.
Telephone has been there for a quite long time... specify that it is the cellphone you talk about.
Well, in the introduction you should introduce your prompt to the reader. Then you should state your position regarding the argument.
Telephone is now being changed overtime and has developed in a new type of phone which is cellphone.
.... this does not sound a strong sentence.
You need to improve on essay structure too.