Cerebrospinal fluid (CSF), clear, colourless liquid that fills and surrounds the brain and the spinal cord and provides a mechanical barrier against shock. Formed primarily in the ventricles of the brain, the cerebrospinal fluid supports the brain and provides lubrication between surrounding bones and the brain and spinal cord. When an individual suffers a head injury, the fluid acts as a cushion, dulling the force by distributing its impact. The fluid helps to maintain pressure within the cranium at a constant level. 
https://www.britannica.com/science/cerebrospinal-fluid
        
             
        
        
        
I believe it’s attitude. Hope this helps!!
        
                    
             
        
        
        
I would say Recycling or using alternate power sources such as solar or wind
        
                    
             
        
        
        
When you take narcotics you can get addicted and when you use it to much you mentally block it out your body gets used to it and you will physically need to take it because you think it’s not working. Once you get addicted you use it so much you could die
        
             
        
        
        
<span>The correct answer is B. following fitness safety basics. If you follow the guidelines that tell you how you should do an exercise, then obviously there aren't going to be any problems and you won't get hurt. You don't need to have the most expensive equipment, or join the most popular gym, or stay at home in order to do that - you just have to follow the rules because they were made by people who know their job well so there that you don't get injured.</span>