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 is learning Ancient Greek language.

The siamang resonates the forest with its distinctive voice.

New World monkeys live in South America.

The black lemur lives in Madagascar.

He always does perfect work, but he made a mistake today. Well, even monkeys fall from trees.