placoid scale

例句：

1. 1. The placoid scales on the fish are a unique feature of its appearance.
   鱼身上的鳞状鳞片是其外观的独特特征。
2. 2.The scientist examined the placoid scales on the animal to determine its age.
   科学家检查了动物身上的鳞状鳞片以确定其年龄。
3. 3. The placoid scales on the tree trunk protect it from damage by insects and other animals.
   树皮上的鳞状鳞片保护树木免受昆虫和其他动物的损害。