What is the percentage of nitrogen in a humans body

What claim did thorne make? what evidence supported his claim?

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

Which kind of worm has a closed circulatory system? a planarian b fluke c pinworm d an earthworm