parasitus

例句：

1. 1. Parasites can cause serious health problems in humans.
   寄生虫可以在人类中引起严重的健康问题。
2. 2. The parasite is causing the host to suffer from severe pain and discomfort.
   这种寄生虫正在使宿主遭受严重的疼痛和不适。
3. 3.Parasites are a major cause of disease in many parts of the world.
   在世界上许多地方，寄生虫是疾病的主要原因。