What is unique about the tongue of the frog?

The function of frog skin is to regulate moisture and fluid transfer. This is why frogs live near lakes, ponds, and streams. This is also why it is not good to hold a frog for too long. Your dry hands will cause the frog's skin to become dry.

Also, most frogs and toads breathe (and take in moisture) through their skin through a process called cutaneous gas exchange, but they also have lungs with which they breathe. This helps in it's early stages of life while living in water.

The function of frog skin is to regulate moisture and fluid transfer. This is why frogs live near lakes, ponds, and streams. This is also why it is not good to hold a frog for too long. Your dry hands will cause the frog's skin to become dry.

Also, most frogs and toads breathe (and take in moisture) through their skin through a process called cutaneous gas exchange, but they also have lungs with which they breathe. This helps in it's early stages of life while living in water.

A frogs skin protects the inside of the frog (like the skin of humans) and it allows for frogs to breathe under water better.
its helps the frog when they are in the water to breathe easily through their skin.
To regulate moisture and fluid transfer.

Well basically a frog drinks through it's skin because the skin is absorbent.