1)preliminary practices ngondro,四加行2)Four stages to the path of application,四加行位3)parallelogram law of addition,平行四边形加法4)C 4 processing,碳四加工5)four color screening,四色加网6)hydrogenation of C_4 fraction,碳四加氢
用法例句
The original combined process for C 4 processing to produce high octane value gasoline in Lanzhou Petrochemical Company was made up of MTBE, polyisobutylene, gas fractionation, polymerization and alkylation units, taking FCC light C 4 distillate as feedstock.
