Alliteration is when two or more words have the same beginning sound. In the poem there are three examples:
1) Though...thy...thou
2) crest...craven
3) shorn...shaven
Alliteration gives the text a more unified rhythm, in a way I guess. It makes the piece sound more together.
Hope this helps!
When they're in a plane that lands in a different timezone
Answer:
no nor no nor no no no no no