Answer:
Reproduction.
Explanation:
Reproduction is the process through which species continue their generation.
 
        
             
        
        
        
Answer:
Brian most clearly exhibits symptoms of ADHD
Explanation:
ADHD stands for Attention Deficit Hyperactivity Disorder is a medical condition where the affected person develops different brain developmental process that leads to poor attention,restlessness,impatient or impulsive etc.
This type of symptoms are mainly found in children and it may lasts upto adulthood.
This type of behviour affect the child in school and at home.
To cure this disease,the affected person should consult the doctor,apply different therapy,medicines are also used to cure this disease.
 
        
             
        
        
        
Answer:
By far, the most abundant gas in the Earth's atmosphere is nitrogen, which accounts for about 78% of the mass of dry air.
Explanation:
 
        
                    
             
        
        
        
Answer:
Symbiotic relationship
Explanation:
An average human body between 20 to 30 year of age with a weight of 74 kg and 170 cm contains about 30 trillion cells. The number of bacterial cells in the same man counts for about 39 trillion that is higher than the cell of the body.
The ratio between the bacterial cell to the human cell is about 1.3:1 which is almost equal or higher than the human cells.
Although the number of bacteria is almost equal or higher than the human cell, the main reason behind this relation is that these bacteria live in the symbiotic or mutually beneficial relationship with humans.
Thus, a Symbiotic relationship is the correct answer.
 
        
             
        
        
        
Answer:
convergent plate boundaries
In general, the deepest and the most powerful earthquakes occur at plate collision (or subduction) zones at convergent plate boundaries.