Which scenario describes a relationship of mutualism? A polar bear catches a seal for dinner.

Oxpecker birds eat parasitic ticks off the backs of zebras.

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

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

hello the answer is B hope this helps

Explanation:

b

Explanation:

check for the pregnancy rating of drug. if its class c or d see if other alternatives

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.