bacterial population density

例句：

1. 1. The study of bacteria is crucial for understanding the health of ecosystems.
   研究细菌对于理解生态系统的健康至关重要。
2. 2. In a hospital, the bacterial population density can be monitored to prevent outbreaks.
   在医院，可以通过监测细菌群落密度来预防爆发。
3. 3. The researchers found that the bacterial population density in the soil was significantly higher than expected.
   研究人员发现土壤中的细菌群落密度远高于预期。