Protozoans are single-celled organisms.

A matrimonial quarrel is one of the factors that disturb the peace of the home.

He was observing wild animals in the grassland.

Collagen is an important component for maintaining skin elasticity.

The development of nuclear-powered ships must consider their impact on the environment.

Freedom of speech is a fundamental element of democracy.

The study of filterable pathogens is an important part of virology.

His work skillfully incorporates elements of modern parody.

She was diagnosed with collagenosis.

We need to find a fundamental solution to this problem.