The infectious diseases are considered as emerging when their occurrences have increased in the past few years and could increase in the coming time like SARS, H1N1, or HIV/Aids.  
On the other hand, the re-emerging infectious disorders are those, which were once considered as the major health issues globally or in a specific nation, and then got diminished drastically, however, are again turning into the health issues for a substantial ratio of the population like tuberculosis and malaria.  
 
        
             
        
        
        
Answer:
A. Sediment
Explanation:
As water flows, it both breaks down rocks and picks up soil. When the pieces of rock and soil are travelling in water, they are called sediment.
 
        
                    
             
        
        
        
Answer:
the challenges they would expect to see is the plants not having water or air
planted need water to have photosynthesis and since theres no water in space and little to no atmosphere the plants would suffocate 
 
        
             
        
        
        
Answer:
Potassium
Explanation:
Potassium forms many important compounds. Potassium chloride (KCl) is the most common potassium compound. It is used in fertilizers, as a salt substitute and to produce other chemicals. Potassium hydroxide (KOH) is used to make soaps, detergents and drain cleaners.