Recall that a period is horizontal, and a group is vertical. 
So if cobalt is moving "down" a period, it would be most logical to say that it would be Ni, or nickel. It could also be Copper, Zinc, Gallium, and so on. Make sense?
        
             
        
        
        
Recessive because If one of your parents has it, you have a small chance of getting it too. 
        
             
        
        
        
B.
When fossil fuels are burned carbon dioxide is released in to the atmosphere 
hope this helps
        
                    
             
        
        
        
Answer 
Option C - Skeletal Muscles 
Explanation 
Antagonistic pairs are the muscles that are functionally opposite, if one produces flexion, then the other's primary action is an extension. Skeletal muscles work in pairs to move a bone so that the muscles can function properly. They contract the bone making nerves deliver a message to the brain. For example. Biceps and triceps. The lower arm is moved upwards when the biceps muscle contracts and the triceps muscle is relaxed and vice versa.