He prefers natural foods.

This wood may spontaneously combust if the humidity is high.

His car spontaneously combusted all of a sudden.

Natural rights are rights that humans have from birth.

We went to the zoo with our family on the weekend.

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

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

He is majoring in zoology at university.

She has zoophobia, and runs away as soon as she sees dogs or cats.

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