You are presented with the question "Frogs breathe through their skin, which is what?" and the following answer choices: 
- poured
 - filtered
 - fibrous
 - warm
 - unique
 - evolving
 - porous
 - fermented

Now knowing that skin is used for breathing air by frogs and for example, the frog is covered with skin that is porous to air, choose the best answer.


 

       porous  