Both television and telephone are the results of the technological development of the modern technology. While television has brought a new era of information with visuals, telephone enabled quick and easy communication between people, no matter how far they are apart. Nevertheless, television is more closely connected to people's lives and people spend more time with television rather than telephone. Thus, I agree that television has had a greater effect on people's lives than the telephone has.
Excellent introduction. Very impressive :) Good structure, grammar, vocabulary, ideas etc.etc. :)
First of all, television is a broadcasting media. Some people might argue that telephone can also act as a medium. However, television is a form of medium that influences how people think. Its role as a medium is so huge compared to the telephone that there are strict regulations for television programs. A lot of people hear news reported from the television and it affects public opinion. This is also related to establishing different kinds of political opinion. In addition, it transmits information widely. Its distribution of information is far broader, faster and more accurate than telephone's.
Include some specific examples to support your reasoning. Also, it is good to have one reason per body para. This arrangement would help you manage time efficiently too because this task has a major bearing on time.
Overall, you have excellent writing skills and with slight improvement in the structure you would surely head for a flying score :)