The human immunodeficiency virus destroys the immune system, making the body unable to fight disease.

This shape is called a gyrobifastigium.

He bought paint to paint the house.

He is an expert in ethology.

My grandfather contracted poliomyelitis when he was young.

Triumph won the game and was very happy.

Workers of the world, unite, the time has come to show our strength.

The International Workers' Association is historically an important organization.

He is a vegan and does not eat any food derived from animals.

He was the first discoverer of that new species of plant.