Words with a first-type accent are particularly difficult in Japanese.

Anthropozoonosis, or animal-derived infectious diseases, have the potential to spread between humans and animals.

The human immunodeficiency virus destroys the immune system, causing the body to lose its ability to fight disease.

The human immunodeficiency virus is the virus that causes AIDS.

The feline immunodeficiency virus can potentially have serious effects on a cat's health.

My cat has been infected with the feline immunodeficiency virus.

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

It is important to learn about the prevention and treatment of the human immunodeficiency virus.

Einstein proposed the theory of relativity.

His actions always have a duality.