动物寄生物病

例句：

1. 1.The parasite is causing the host to suffer greatly.
   这种寄生虫正在使宿主遭受极大的痛苦。
2. 2.Parasites are often found in environments where they can live off of other organisms.
   寄生虫通常存在于它们可以依赖其他生物生存的环境中。
3. 3. Some people believe that parasites are responsible for spreading diseases.
   有些人认为寄生虫是传播疾病的原因。