Giardia

例句：

1. 1.Giardia is a type of parasite that can cause diarrhea.
   贾第虫是一种寄生虫，可以引起腹泻。
2. 2. The water was contaminated with Giardia, making it unsafe to drink.
   水被贾第虫污染，不能饮用。
3. 3. Researchers are trying to find ways to prevent the spread of Giardia in public water systems.
   研究人员正在尝试寻找方法来防止公共水系统中贾第虫的传播。