Daylight is fading away, night silhouettes in the sky LED lights are flashing on towers
It's Manhattan's magical time
Ballerinas dancing the Swan Lake
On a river made of diamonds and pearls
Everything's a little bit weird now
Because tonight, it is showtime
In the middle of the street life
All we celebrate are good times
Because tonight, it is showtime
Come and walk with me
1273 down the Rockefeller street
Life is marchin' on, do you feel that?
1273 down the Rockefeller street
Everything is more than surreal

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.

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.