William gilbert used a terella in an attempt to explain .
a. unlike poles of a magnet attract.
b. why compasses point toward the north and south poles of the earth.
c. the properties of lodestone.

abruptly

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.