我的鱼缸里有几条色彩鲜艳的灯鱼一起游动。

My aquarium has several brightly colored ___tetras swimming together.

这种细菌感染需要用四环素治疗。

The bacterial infection requires treatment with ___tetracycline.

术语'tetrapod'指的是有四条肢体的动物。

The term '___tetrapod' refers to animals with four limbs.