Yes it is, it has a period therefore a complete sentence.
The symbolic significance of The raven in the poem is vast.The ebony bird stands as the embodiment of grief caused by loneliness and separation.He stands as a symbol of the loss of the narrator whose heart yearns for his beloved Lenore.The raven represents evil and death. hope this is helpful :)
A.
Complex sentences have a lot of words and go into further detail than a basic sentence.
Thomas Eliot works multiple themes in the poem, however in general, his usage of imagery mainly represents ageing and decay. In the lines "When the evening is spread out against the sky / Like a patient etherized upon a table", the phrases like "sawdust restaurants" and "cheap hotels," the yellow fog, and the afternoon "Asleep...tired... or it malingers", represent decay. The character's concerns about his hair and teeth which is mentioned in the lines "Combing the white hair of the waves blown back / When the wind blows the water white and black," show the problems about aging.