He is majoring in zoology at university.

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.

My child attends a supplementary school every Saturday.

Gender identity refers to the gender that each individual recognizes themselves as.

He likes to take a walk in the park at dusk.