Answer:
stone is stone , the most beautiful stone it is right I think
 
        
             
        
        
        
Background extinction refers to the normal extinction rate. These are species that go extinct simply because not all life can be sustained on Earth and some species simply cannot survive. Mass extinction is a widespread event that wipes out the majority (over 50%) of living plants and animals.
        
             
        
        
        
Answer:
It will remain constant...
Explanation:
In accordance with the Mendel's law of segregation, independent assortment as well as Hardy-Weinberg Theorem., no matter what type of cross within the homozygotic characteristics takes place, the frequency of dominant and recessive will remain constant over the whole population even if selective breeding strategy is applied. 
For example, the ratio for a single trait of allele will remain 3:1 for a whole population of large numbers
 
        
             
        
        
        
Sulfuric Acid is a diprotic acid and as such a binary acid.  This is because it possesses two hydrogen as denoted by its formula H₂SO₄
Hydrochloric Acid  -  HCl
Phosphoric Acid -  H₃PO₄
Nitrous Acid  -  HNO₃
        
                    
             
        
        
        
b. the first stage because it could never be in the secound stage