Viruses infect and live inside the cells of living organisms.
Influenza viruses mutate.
Influenza can infect and live inside the cells of living organisms.
What can infect and live inside the cells of living organisms?
[1] Leptospirosis
[2] fish
[3] spiders
[4] Pesticides
[5] influenza
[6] horses
[7] insects
[8] bacteria