Proterozoicus

例句：

1. 1. The protozoa are tiny organisms that live in water and on land.
   原虫是生活在水和陆地上的微小生物。
2. 2.The protozoa play a crucial role in the ecosystem by breaking down organic matter.
   原虫在生态系统中起着至关重要的作用，通过分解有机物质。
3. 3. The discovery of protozoa has led to new insights into the evolution of life.
   原虫的发现为生命进化提供了新的见解。