The repeats which occur together on a chromosome are referred to as VNTR. The length of each repeat is 60bp. 
The first primer is 20bp and is 53 bp away from 1st repeat. Therefore, the total length of sequence amplified by the first primer till 1st repeat = 20+53 = 73bp. Beyond this point 6 repeats on 60 bp are present, hence, the length becomes = 73 + (60X6) = 433bp. 
Now the reverse primer which is 21bp in length is located 28bp from the repeat on its side. Reverse primer comes from the opposite direction, so it must be present after the 6 repeats. 
The total length of the amplified region = 433 + 28 + 21 = 482 bp.
 
        
             
        
        
        
I think it’s it will rain tomorrow
        
                    
             
        
        
        
Answer: Sulfur oxide,carbon dioxide and Nitrogen Oxide are acid anhydride.
Explanation: they are refer to as acid anhydride, because when they dissolved in water,they make the water acidic by reducing the Ph of the water.These gases are greenhouse gases that are released into the atmosphere by human activities like combustion, burning of bushes etc,.when they are released into the atmosphere and have contact with atmospheric water, it leads to acidic rain.