Animal experiments are necessary for the advancement of science, but there are also ethical issues.

He is learning about the handling of experimental animals.

Vertebrates are organisms whose part of the skeleton is composed of a spine.

Wild animals are part of nature, and we should protect them.

I enjoyed a picnic in the park.

Children can touch the animals at the zoo.

The children are playing in the park.

A tardigrade can survive in extreme environments.

The characteristic of annelids is that their bodies are divided into ring-shaped segments.

He is an expert in ethology, and his research is highly regarded worldwide.