| 英文同义词: | alkenes, ethylene-manuf.-by-product c5-cut, oligomers, polymers with steam-crac;Alkenes, ethylene-manuf.-by-product C5-cut, oligomers, polymers with steam-cracked petroleum distillates;alkenes, ethylene-manuf.-by-product c5-cut, oligomers,polymers with steam-cracked petroleum distillates;Alkenes,ethylene-manuf.-by-product C5-cut,oligomers,polymers with steam-cracked petroleum distillates;ked petroleum distillates;distillates, petroleum, steam cracked/ alkene oligomers |