The answer is
C. Both systems help remove carbon dioxide from the body.
100% Verified!
Hope This Helps!:)
        
             
        
        
        
Answer:
Channel proteins form hydrophilic channels to passively transport substances down the concentration gradient.
Carrier proteins bind to substances to transport them actively against the concentration gradient. They do not form channels.
Explanation:
Channel proteins are the membrane proteins that serve in transport of small polar molecules and/or ions by making a hydrophilic pore across the membrane. These molecules diffusion through the pore and exhibit facilitated diffusion.  
Carrier proteins are the membrane proteins that transport the substances across the membrane by binding to them. They do not form the hydrophilic channels. Carrier proteins serve in the active transport of molecules against the concentration gradient.
 
        
             
        
        
        
The answer is B. 
If you put one plant in wet soil, and one plant in dry soil, you can prove or disprove your hypothesis as the plants grow. 
 
        
             
        
        
        
A stable ecosystem is characterized by having a continual input of energy from the sun. This is required in order to sustain or maintain a stable structure. Without proper supply of energy, life would not exist. Hope this answers the question.