Fact 1: Gills are used for breathing water by aquatic animals.

Fact 2: Fish gills take oxygen from the water as it passes over the gills.

Given the two facts above, answer the question "What do aquatic animals breathe with?" with the following options: 
- Water
 - tails
 - nose
 - air
 - gills
 - oxygen
 - lungs
 - mussels


 

     gills    