It would be d because a cell is least complex and organ system is most complex
        
             
        
        
        
Answer: The correct answer for the fill in the blank is B) RNA and Proteins.
Ribosome is a molecular machinery, which is located in all living cells. It is formed from proteins and complexes of rRNA ( ribosomal RNA). That is why, it is also called as ribonucleoprotein.
Ribosome serves as the site for protein synthesis. It is primarily divided into two subunits, a larger ribosomal subunit and a smaller ribososmal subunit, which together assist the process of protein formation ( translation).
Thus, the components of ribosomes are RNA and proteins.
 
 
        
                    
             
        
        
        
Answer:Toothed whales do not make the long, low-frequency sounds known as the whale song. Instead they produce rapid bursts of high-frequency clicks and whistles. Single clicks are generally used for echolocation whereas collections of clicks and whistles are used for communication.
 
        
             
        
        
        
piles known as moraines I’m pretty sure
        
             
        
        
        
Answer:
1. B
2. A
3. D
Explanation:
plz mark brainliest if right. sorry if wrong