A monomer is the basic unit that binds chemically to other molecules to form a polymer . 
For lipids, the monomers are glycerol and fatty acids.
This might help you understand 
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<span>The correct answer is c. Rural communities were built based on the location of available resources. This means that places that had good land for crops or good climate had communities based around crops or tobacco, while comunities based around mining would be near mountains where mines could be found. Rural communities are usually based around some natural resource like a river or a mine or anything similar.</span>
        
             
        
        
        
It is sensors :) i hope this helped you :)