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.

He starts talking about himself at every opportunity, causing trouble for the people around him.

My father will turn 61 years old this year.

I received a New Year's gift from my grandparents on New Year's Day.