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.
The answer is d to the question!!!
The ones about enzymes are chemical digestion and the ones about chewing are mechanical digestion.
Epithelial tissue covers the body, lins internal surfaces, and forms glands.
It is true they do have internal fertilization. This is also one of the reason why it is easy to differentiate between a male or a female shark on birth due ot internal fertilization. <span />
