A vaccine is a medical material that mimics the pathogen, but in a harmless way. When our body's immune fights it off, it remembers how to fight the real pathogen when it enters our body. So, it protects us from diseases.
 
        
             
        
        
        
Answer:
In this case ,the parallel Ray's coming from distant objects are focused in front of the retina. Then again if we use convex lens , it converger more . As a result , person can't see. Due to this reason , short sightedness can't be corrected by use of a convex lens
 
        
             
        
        
        
Answer:
D
Explanation:
Biomass are basically organisms with organic mass. May be living or already dead. Hence, as any organism has biomass, biomass is plentiful. However, as biomass is not pure carbon compound that can fully decompose, toxic gases, carbon monoxide may be produced from incomplete combustion will lead to air pollution. 
 
        
                    
             
        
        
        
Answer:
El Nino because of strengthening of trade winds!
Explanation:
Took this quiz <3
 
        
                    
             
        
        
        
Ok sure im free whats the questions