What's this?
microscope
What's this?
disease
What's this?
bacteria
What's this?
paralyzed
What's this?
mucus
What's this?
immune
What's this?
swallow
What's this?
Common Cold
What are these?
cells
What's this?
scrape
What's this?
influenza
What's this?
virus
What's this?
infect