C. Decreased death rate is the answer
        
             
        
        
        
Mass is measured by using a balance comparing a known amount of matter to an unknown amount of matter. Weight is measured on a scale.
 
        
             
        
        
        
Answer:
B.
burning of fossil fuels
it increase the amount of carbon present in atmosphere. 
 
        
                    
             
        
        
        
Answer:
<em>IAU- International Astronomical Union</em>
Explanation:
The  International Astronomical Union (IAU) is an organization consisting of professional astronomers from around the whole world. The astronomers in the  International Astronomical Union (IAU) work together to assign names and probable functions of different celestial bodies being discovered. The aim of the  International Astronomical Union (IAU) is to protect and to safeguard field of astronomy and make progress in this field.