Answer: The primary motor cortex for control of voluntary muscles is found in the precentral gyrus of the frontal lobes.
Explanations:
The primary motor cortex is one of the important brain areas involved in motor function. It is found in the precentral gyrus of frontal lobes. It control voluntary muscles and generate impulses needed for movement execution.
Voluntary muscles are muscles that we can control consciously or we can control them at will and we can choose when we want to use them. They are also refers to as skeletal muscles and are attached to bones. The are majorly use for locomotion.
 
        
             
        
        
        
<span>the interference of two waves of equal frequency and opposite phase, resulting in their cancellation where the negative displacement of one always coincides with the positive displacement of the other.</span>
        
                    
             
        
        
        
 they contain half of a set of chromosome...that's jot true
 
        
             
        
        
        
Answer:
A. Whales evolved from four-legged animals.
Explanation:
I'm 100% on this one, because on Plato we were learning about evolution, and one of the slides said that whale had evolved from four legged animals. 
Hope this helps ya!!!
Got a screenshot for proof!