Question

in the line 'yet not a soul knew which' what is the thing that the poet is reffering to that no one knew and why
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Answer 1

mantle is a layer inside a planetary body bounded below by a core and above by a crust. Mantles are made of rock or ices, and are generally the largest and most massive layer of the planetary body. Mantles are characteristic of planetary bodies that have undergone differentiation by density.