A general rubric does not evaluate the supporting details in a piece of writing.
Answer:
(fill in the blanks so it applies to your school and situation)
Dear _________ (your friend's name),
How are you? I hope you are well. I am doing great. That is, except for with school. My school is having some problems with _________(a problem at school). It's a big deal to me because ____________(how the problem affects you). Is your school struggling with this as well?
I would love some advice.
Sincerely, ____________(your name)
