1. Petrochemistry is the branch of chemistry that deals with the chemical processes and transformations that occur in petroleum.（石油化学是处理石油中发生的化学过程和变化的化学学科。）

2. The petrochemistry industry plays a crucial role in the production of various petrochemical products such as plastics, synthetic fibers, and rubber.（石油化学工业在生产塑料、合成纤维和橡胶等各种石油化工产品中起着至关重要的作用。）