The nervous system may be compared to a " A computer
B trash removal company
C highways in a city
D water filtration center

A. A computer

Explanation:

The way your nervous system works can be compared to how your computer works. When you press the power on your computer, a signal goes out. The signal is a catalyst that generates a number of actions and responses. An electric current travels over the wires maintaining a connection to electricity

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.