petrochemical unit

例句：

1. 1.The petrochemical unit is responsible for producing chemicals and fuels.
   石化联合企业负责生产化学品和燃料。
2. 2. The petrochemical unit is a major employer in the region.
   石化联合企业是该地区的主要雇主。
3. 3.The petrochemical unit has been undergoing significant expansion in recent years.
   石化联合企业近年来经历了显著的扩张。