The primary and most significant greenhouse gas emitted from human activities is carbon dioxide. Burning of fossil fuels is the major cause of increased carbon dioxide emission.The burning of coal, oil, and natural gas is an important energy source to produce electricity.
        
             
        
        
        
The answer is: An air conditioner that turns on if the temperature gets too hot.
Even though they hurt you emotionally, Negative feedbacks serve their own important function. They keep your feet on the ground and prevent you from getting too arrogant.
This function is similar as a cooling air conditioner. Hot temperature in the comparison above represent your arrogance and the air conditioner represent the negative feedback.
 
        
                    
             
        
        
        
9 is letter d and 10 is a
 
        
             
        
        
        
A is the correct answer to the question
        
             
        
        
        
Moon: Not magnetic
Compass: Permanent Magnet
MRI: Not Magnetic