Answer:
Kombucha is a Symbiotic culture of bacteria and yeast (SCOBY), similar to mother of vinegar, containing one or more specie each of bacteria and yeast which is added to sweet tea, which jump start two processes take place. First, alcoholic fermentation during which the yeast convert sugars to alcohol under controlled conditions. After that, the bacteria converts most of this alcohol into acetic, gluconic and glucoronic and other organic acids. during both of this processes, the yeast and bacteria, feast and multiply, yielding an end beverage that is rich in variety of micro organisms and healthy acids. Source: Health-Ade.com/blog/blog/what-is-fermentation
the products formed is more rich than those of the fermentation of grapes because it is a symbiotic fermentation of yeast and bacteria
Explanation:
Kombucha is fermented slightly alcoholic, lightly effervescent sweetend black or green tea, commonly consumed for its health benefits sometimes the beverage is called kombucha tea to distinguish it from the cultures of bacteria and yeast. Kombucha is thought to have originated in manchuria where the drink is traditionally consumed or in Russia and Eastern Europe.
Source: "A mug Of Kombucha for your health?" .<em>mayo clinic. </em>Retrieved 2018-09-01
Answer : The balanced chemical equation is,

Explanation :
Balanced chemical equation : It is defined as the number of atoms of individual elements present on the reactant side must be equal to the number of atoms of individual elements present on product side.
The given unbalanced chemical reaction is,

This chemical reaction is an unbalanced reaction because in this reaction, the number of atoms of individual elements are not balanced.
In order to balanced the chemical reaction, the coefficient 2 is put before the
, the coefficient 3 is put before the
and the coefficient 4 is put before the
.
The energy evolved in this reaction = 
Thus, the balanced chemical reaction will be,

First, we must know what happens in the precipitation reaction. This type of reaction is a double replacement reactions. It is consists of two reactant compounds which interchange cations and anions to form two products. One of the products is an insoluble solid called a precipitate. For the precipitation of CaCO₃, there are two consecutive reactions involved:
1. Slaking of quicklime, CaO
CaO + H₂O ⇒ Ca(OH)₂
2. Precipitation
Ca(OH)₂ + CO₂ ⇒ CaCO₃ + H₂O
The ions that make up the H₂O molecule are H⁺ and OH⁻. According to solubility rules, the cation (positively charged ion) is likely to be attracted to an anion (negatively charged ion). Together, they form an ionic bond. This type of bond is when there is a complete transfer of electrons between the two. The Ca²⁺ cation lacks 2 electrons, while the anion OH⁻ has an excess 1 electron. In order to be stable, 1 Ca²⁺ ion and 2 OH⁻ ions must combine.
Therefore, the answer is OH⁻ ion.
Answer:
They are due to past earthquakes