Answer:  This is a positive feedback loop.
Explanation:
The protein digestion in the body is an example of the positive feedback. The gastric secretions is stimulated chiefly by the action of three chemicals.
These chemicals are acetylcholine, histamin and gastrin. These chemicals stimulate the parietal cells to secrete HCL and intrinsic factors. 
The chief cells secrete pepsinogen in response to the gastrin and ACh. As the dietary proteins are digested, it breaks down the amino acids and peptides.
This stimulates the G cells of the stomach to secrete more gastrin. This is how the positive feedback loop for the protein digestion works.
 
        
             
        
        
        
Carrying compacity affects communities because there is usually limited resources. If a population gets too high, they may die out.
        
                    
             
        
        
        
Answer:
Long relaxing swim.
Explanation:
Muscle is one of the most important tissue of the body that helps in the control and the coordination of the body movements. Three different types of muscle are smooth muscle, cardiac muscle and skeletal muscle.
The red fibers are the slow twitch fibers that contains large amount of stored oxygen in their muscles. These fibers can generate ATP by the fat and the glycogen metabolism. This fiber will help the swimmers to obtain energy at the end of the race to overcome the oxygen deficiency.
Thus, the correct answer is option (C).
 
        
             
        
        
        
2................................................