B. Walking is an easy and safe exercise for beginners
        
                    
             
        
        
        
<span> A. Problem/solution
This paragraph starts by identifying the problem that NACA faced: they needed more computers. The solution is then described in detail. They ended up hiring women, and the paragraph goes on to show how and why the number of women and the racial diversity at NACA grew over the next ten years. </span>
        
             
        
        
        
Answer:
opening and cavern
Explanation:
Both have meanings similar to grotto 
 
        
             
        
        
        
Answer:
This is hard one  but i think if you looked that up it will show an answer for it
Explanation: