Writing is today a much different task than it was 20 years ago. (2)Back then, writers had only to be proficient in two areas: correspondence letters and (for students) academic essays. (3)Effective writers today must master many more realms, including email, IM, social media, and texting. (4)Each of these forms of writing have different rules of style that can, if we're not careful, grow confusing. (5)The essence of all writing, however, has not changed over the years. (6)It is the act of moving exciting ideas from your mind to the minds of your audience. Which is a supporting sentence?