Answer:
c) The presence of an ephiphyseal line
Explanation:
The options should be:
a) the presence of osteoblasts 
b) the presence of osteons 
c) The presence of an ephiphyseal line
d) the presence of hyaline cartilage on the ends of the bone
Explanation:
In vertebrates, the epiphyseal line is formed once the bone is completely grown. This occurs inside a plate known as the epiphyseal plate.
From the age of 18 to 21, the bone stops growing and the cartilage inside this plate gets replaced by bone. However, bones can keep growing in width until we are approximately 25 years old.
Therefore, the physical sign that indicates that a bone cannot continue longitudinal growth would be the presence of an ephiphyseal line.
 
        
             
        
        
        
I am pretty for sure the answer is roots.
        
                    
             
        
        
        
I believe it is 'white fur' because living in the Tundra means it is snowing. Snow is white, so basically, the white fur is specifically for the Tundra.
I hope it helps.
 
        
             
        
        
        
Answer:
6. Because of how old the rocks are
Explanation:
6. Sedimentary rock forms in layers because of the order they were formed. The older rocks will form first and as time goes on, rock forms above it to create a new layer, and  so on. 
 
        
             
        
        
        
Answer:
A and B
Explanation:
Only plants have cell membranes and chloroplast.