He is cutting vegetables with a kitchen knife.

He is our class representative.

He was diagnosed with schizophrenia.

Countries around the world are caught up in an arms race.

He was diagnosed with schizophrenia.

Coelenterates are said to be the first animals with a true body cavity.

He is an expert in primatology and is engaged in the study of gorilla behavior.

A mute swan was swimming in the park's pond.

A black-necked swan was swimming in the park's pond.

He was moved by the view from the top of the skyscraper.