Protozoans are single-celled organisms.

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

The wildfire burned down the entire forest.

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.

We need to find a fundamental solution to this problem.