乌龟是一种慢动物，它们通常行动缓慢，很少跑得很快。它们有一个坚硬的外壳，可以保护它们不受伤害。如果用英语描述乌龟，可以这样说：

The turtle is a slow-moving animal that usually doesn't run very fast. They have a hard shell that protects them from harm.