Analyze the polymer polypropylene. Three dots then C connected by single lines to H above and C H subscript 3 below. Then a single line to a C connected by single lines to one H each above and below. Then a single line to a C connected by single lines to H above and C H subscript 3 below. Then a single line to a C connected by single lines to one H each above and below. Then a single line to a C connected by single lines to H above and C H subscript 3 below. Then a single line to a C connected by single lines to one H each above and below. Then three dots. Which element forms the skeleton of this polymer? carbon copper hydrogen oxygen