The brown stuff is called plaque. This forms on your teeth when you eat and its something you can't get rid of. There is tooth paste that can help maintain it.
Unhealthy weight gain may cause heart disease, stroke, cancer, and many other diseases. Hope it helps! :) If you could vote my answer as the brainiest, that would be awesome! :)
Answer:
Esophagus
Explanation:
esophagus provides a passway between the mouth and stomach otherwise it has no other major function in digestion, absorption and elimination
