Answer:
silica
Explanation:
Diatoms are microscopic organisms.  they have  shell that is made from organic compounds and silica.Diatoms contain silica in their cell walls. This material is used industrially in the production of toothpastes, silver polishes, and swimming pool filters. Silica is used to remove  stains and debris.
 
        
             
        
        
        
Taproot and Fibrous roots
        
             
        
        
        
Answer:
D most likely. As the moon revolves around Earth, the different amounts of the sunlit side faces Earth
Explanation:
We never really see the other sides of the moon, it's always facing one side to us.
 
        
                    
             
        
        
        
Answer:
i think it is.. a mass of cancer cells
Explanation:
 
        
             
        
        
        
The nervous system in a frog controls the activities of the organs of the body. It also would regulate the internal environment in one's body. All the organs which are also the same parts of nervous system of a vertebrate are present in a frog. The brain,spinal chord,the sympathetic and para sympathetic nerves,cranial nerves,spinal nerves,cranial nuclei and ganglia.