secondary enrichment

例句：

1. 1. The process of secondary enrichment is crucial for the growth of microorganisms.
   次级富集过程对于微生物的生长至关重要。
2. 2. The research on secondary enrichment has led to significant advancements in biotechnology.
   次级富集研究在生物技术领域取得了显著进展。
3. 3.The secondary enrichment method is widely used in the field of environmental science.
   次级富集方法在环境科学领域得到了广泛应用。