Answer:
13
Explanation:
it get recycled again when it becomes old
 
        
             
        
        
        
Answer:
Unequal heating of the earth
Explanation:
Warm air rises at the equator and moves towards the poles. At the poles,  the cooler air sinks and moves back to toward the equator
 
        
             
        
        
        
Fitness. Give me brainliest please
        
             
        
        
        
<span>The correct answer is d. the idea that T. rex held its tail aloft was supported by the studies of many scientists. This is how science works, things are discovered by having members of the scientific community do experiments and come to the same conclusion. Many of them confirmed this theory and a concensus was established.</span>
        
                    
             
        
        
        
Thin, flexible barrier around a cell; regulates what enters and leaves the cell 
- contains the cytoplasm (all interior cell organelles and the cytosol) - allowing the chemical reactions in the cell to occur
<span>- semipermeable (or selectively permeable) - allows certain substances in, keeps others out </span>
<span>- offers limited protection</span>