Table sugar is not a mineral because it is in crystal for it is made of more than one element it is not made by a geologic process its chemical composition is always changing

it is not made by a geologic process  

Explanation:

A mineral is any substance or compound which is generated by the geological processes under the surface of earth crust. It is typically inorganic and is not produced by any of the biological process or by the use of any biological agent. They are formed by the solidification and crystallization of magma after the volcanic activities.

The table sugar is not a mineral because it is composed of an ingredient which comes from a biological source that is sugarcane. The formation of sugar crystals from the sugarcane juice is a chemical process. It does not follow geological processes.

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.