Please help with this.

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

The first amino acid of a new polypeptide chain is

At which point is crust neither created nor destroyed? island chain mid-ocean ridge divergent boundary transform boundary