What do your cells have to overcome the problem of needing high activation energy?

They use enzymes.

Explanation:

Cells employ enzymes to drive and speed up their chemical reactions without being used up themselves. They are the only macromolecular biological catalysts that can start a reaction using the smallest available heat energy, thus overcoming the issue of needing high activation energy. Enzymes work by converting specific substrates to required product by binding them to their active site.

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.

i am sorry but i need more information and a picture.