The correct answer is: marsupials. 
Marsupials are actually defined by their ability to hold the young in the pouches, where they can be well protected. Some examples are Kangaroos and Koalas. 
Other answers are wrong: for example, gymnosperms are plants, not animals. 
        
             
        
        
        
the answer is c. ecosystem i got a 100% on the test
 
        
                    
             
        
        
        
They do lower the activation energy but they provide an alternate pathway for the reaction to happen quicker and they do not get used up in the reaction
        
             
        
        
        
Answer:
seleccion natural, habilitar
english translation: natural selection, and habilitate.
 
        
             
        
        
        
The smallest type of stream is a brook.