Mammals can maintain a constant body temperature.

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

He is learning about the handling of experimental animals.

Roundworms are an important part of the soil and contribute greatly to the health and fertility of the soil.

He is a world-renowned zoologist.

My pet is a dog.

Finding an asterism is a great joy for astronomers.

Looking down at the sea, I could see a school of fish swimming.

Please choose the correct one from the set of possible answers to this question.

It's very exciting to see a crowd of horses running at the racetrack.