Why do the characters arrive at the secret annex wearing several layers of clothing? the weather is unusually cold. there is no heat in the secret annex. they think carrying luggage would look suspicious.

They think carrying luggage would look suspicious

hope I helped

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.