Who wants to be my boy frind for 71 points im 13

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

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?

This is a scaffolding of protein fibers that us sell keep it shape in a cell division and cell movement