Norder to use more natural sounding language, you should use a dictionary or thesaurus to replace as many small words as you can. nothing. keep all the words in your original writing. only words for which you know the meaning. the words you do not think your teacher will like.

Synonyms are the way to go when you're trying to replace small words with similar definitions. You can easily find websites that will help convert words and show all the different synonyms of them. Thesauraus is a great website for this.

the sentence that avoid faulty coordination is:

culture, which is well represented in philadelphia, plays a major role including theatre, music, and the visual arts.  

faulty coordination occurs when the writer gives equal importance two different ideas (clauses) which in fact are not equivalent. in order to correct a misplaced clause or idea, the writer can place less important or emphatic ideas in a relative clause as in the previous sentence.  

c) vampires in history and modern life.