Fact 1: Most amphibians breathe with gills as larvae and with lungs as adults.

Fact 2: All frogs are amphibians.

Given the two facts above, answer the question "What can breathe with gills as larvae and with lungs as adults?" with the following options: 
- humans
 - viruses
 - a fish
 - animals
 - bats
 - frogs
 - bacteria
 - air


 

      frogs   