Give abbreviated structures of each of the following compounds: 

(a) (E)-1,4-poly-2-methyl-1,3- butadiene [(E)-1,4-polyisoprene]; 

(b) 1,2-poly-2-methyl-1,3-butadiene (1,2-polyisoprene); 

(c) 3,4- poly-2-methyl-1,3-butadiene (3,4-polyisoprene); 

(d) copolymer of 1,3-butadiene and ethenylbenzene (styrene, C6H5CH P CH2, SBR, used in automobile tires); 

(e) copolymer of 1,3-butadiene and propenenitrile (acrylonitrile, CH2P CHCN, latex); 

(f) copolymer of 2-methyl-1,3-butadiene (isoprene) and 2-methylpropene (butyl rubber, for inner tubes).