Fact 1: Breathing is when a gill converts from oxygen in water into oxygen in blood.

Fact 2: All fish have gills .

Given the two facts above, answer the question "When fish convert oxygen in water to oxygen in blood this is called?" with the following options: 
- evaporation
 - barrel-shaped
 - motility
 - Heart rate
 - squeeze
 - breathing
 - hormones
 - survival


 

      breathing   