Thank you for the replay,Gillnetter.
I know I am doing some silly mistakes while using articles. I took only half an hour to collect the data and to write the essay as I was busy with my work. Another silly mistake is, using 'often' beside 'sometimes'. Actually, I supposed to use 'even' instead of 'often'. Unfortunately, I have submitted this essay with all these mistakes to meet the deadline. I've submitted 10 essays in total. I ran out of time for the last three essays to proofread. ....anyway...thank you.
My target college is MICA( Mudra Institute of Communication). It is one of the best b-school for communication studies in Asia. It looks for a candidate with strong written communication skills. The entrance exam is on Feb 20th. I have 24 days to improve my w.comm skills.