Answer:
Menstruation is one part of a person's menstrual cycle which includes the shedding of the endometrium (lining of the uterus) that occurs throughout a person's reproductive life.
 
        
             
        
        
        
Answer:
An earthquake
, a forest fire
, a hurricane  and a volcanic eruption.
Explanation:
An earthquake
, a forest fire
, a hurricane  and a volcanic eruption are the events that is responsible for the suitable conditions for primary succession because all the population of animals and vegetation are removed from an area and the new type of organisms is start to living in that new environment. These new organism has the ability to survive that environmental conditions. These events completely removed the population in the environment and provides conditions for primary succession.
 
        
             
        
        
        
Answer: A.They contain plants that purify water.
 
        
                    
             
        
        
        
Answer: The process of change in the living parts of the ecosystem is called succession.
Explanation: Change-And ecosystem changes over time and can undergo development through a process called succession.
 
        
             
        
        
        
I believe the correct answer would be the third option. Our elements that comprise over 95% of the human body are <span>carbon, hydrogen, oxygen, nitrogen. Carbon and hydrogen is the backbone of any hydrocarbon or organic compound. The cells in our body are made up organic compounds thus our body is mostly composed of carbon and hydrogen. Oxygen is also present in high percent in our body since it is important for the processes of the cells. Also, nitrogen should be present in our body in large amount since it is present in proteins which is found in our body's cells and tissues.</span>