Doesn't cadence mean 'the rise and fall in pitch of the voice'? How does that apply to a written letter? I'm confused.
This is such a great question!! I think I found an answer for you.
Google this: cadence in writing
Also, check this out carefully.
thefreelibrary.com/Good+writing+needs+cadence.+(Symposium+Secrets+to+Stronger...-a0102908476
'elements of language'
Elements of language... google this: figures of speech, list
Also, I found some good info by googling this: elements of language
Really, the teacher seems to be being unclear unless "elements of language" were studied in class.
But anyway, just do your best. You have to read the speech 3 times, and then look at the letter. :-) You will see common strategies in the use of language: rhythm, alliteration, repetition... etc.
I do not know if logos, ethos, and pathos are what the teacher is refering to. They are the elements of classical rhetoric, but I don't know if that is what she is referring to.
:-)