Which of the following describes a relationship of commensalism?

a. oxpecker birds eat parasitic ticks off the backs of zebras

b. the tapeworm latches itself in the intestines of a rat feeding off all the nutrients eaten by the rat

c. a polar bear catches a seal for dinner

d. birds feed off the insects that are stirred up from the grasses as cattle move through

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explanation:

bacteria could be both, harmful and to us. harmful bacteria could make us sick and probably even by getting the chances of getting a disease, but good bacteria fight it off with your immune system. there is always bacteria everywhere we go. we need to make sure to wash our hands after using the restroom, before eating, after eating, after petting an animal too. so you see, bacteria is everywhere and is harmful or . i hope this . : ) : ) : )