变形虫

例句：

1. 1.The bacterium can change its shape to avoid detection by the immune system.
   这种细菌可以改变形状，以避免免疫系统的检测。
2. 2.Scientists have discovered that some amoebas can change their shape to fit into narrow spaces.
   科学家们发现一些变形虫可以改变形状，以适应狭窄的空间。
3. 3.Amoebas are a type of single-celled organism that can change their shape and size to survive in different environments.
   变形虫是一种单细胞生物，它们可以改变形状和大小，以适应不同的环境生存。