It's a biological reaction to dangerous situation.

这是面对危险情况时的生理反应。

For example, it helps get rid of waste and regulates temperature, and it provides a medium for biological reactions to occur in the body.

例如，它帮助排出废物，调节体温，并对身体内的生理反应提供介质。

Some of the most important include settling tanks to remove large particles, biological reaction tanks where microbes eat unwanted materials, and chemical disinfection processes that kill pathogens.

其中最为重要的步骤包括沉淀池中去除大颗粒，生物降解池中多余物质由微生物分解，以及化学消毒杀死病原体。