The brain operates on two levels, conscious and unconscious. this is called:

Answer : The correct answer is -

A two track mind.

The brain operates on two levels, which are the level of consciousness (awareness) and unconsciousness (that is not related to awareness).

In other words, our perception, thinking, memory all operates at two levels (also called dual processing) that are conscious (which is a highly controlled, explicit level) and unconscious (implicit, non controlled, automatic level).

This is termed as two track mind.

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.