In literature a symbol can be subtle or obvious. In 'The Raven' the symbol is obvious. Poe himself meant the Raven to symbolize 'mournful, never-ending remembrance.' Our narrator's sorrow for his lost, perfect maiden Lenore is the driving force behind his conversation with the Raven
        
             
        
        
        
The poem has an abcb rhyme scheme.
Each stanza is a quatrain.
The poem contains two stanzas.
These three statements are correct. The poem has an abcb rhyme scheme. The rhyme scheme is determined by the last words of each line. The first line of the stanza is labeled a. The second line ending with shore does not rhyme with pass so it is labeled b. Stretched does not rhyme with either of the two preceding lines so it is labeled c. The last line of the stanza, more, rhymes with shore. It must be labeled b just like the second line. This results in the abcb rhyme scheme. It is the same in the second stanza. A quatrain is a stanza with four lines. Each of the two stanzas is made up of four lines so they are both quatrains. 
 
        
                    
             
        
        
        
Preposition is a word that indicates location so with that said....
 pocket: I put the keys in my pocket (location)
 bed: I put my shirt on my bed (location)
 cushions: I set the vase down on the cushion (location?)
 afternoon is a time. so the answer is afternoon