WILL GIVE BRAINLIEST The main difference between the water cycle and the other chemical cycles is that water

never changes its structural form (H2O) .

is much slower than the other cycles.

creates completely new substances.

is made from matter that has been here since the world was formed.

The answer is A.

Explanation:

Other cycles change their structural form often, but water does not change it's structural form in the water cycle, which is H2O so that is one main difference between the water cycle and oither checmical cycles. So, your answer is A.

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.