A. moisten is the best answer u got
They breathe through their skin. Air dissolves on the mucus of their skin, so they MUST stay moist to breathe. If worms dry out, they suffocate. As fresh air is taken in through the skin, oxygen is drawn into the worm's circulatory system, and the worm's hearts pump the oxygenated blood to the head area.
Answer:
submarine mountain ranges called oceanic spreading ridges.
Explanation:
The main reason for the species extinction is for the ecological changes.
