You'll need a haircut when you first join.
Four years
There are many ways one can get started in a military career. One is to enroll in the ROTC in high school and continue that into a career. Someone can also enter after college.
teach ROTC
The end of mandatory ROTC
It take 4 weeks sometime during the summer months...there are different "Regiments" and ROTC members start at different dates.
long hair
Enroll in a beauty college. They teach hair and nails. You can do one or both. Takes about 6-9 months of school.
Long hair is in.
A girl's hair is long because the girl made a decision to have long hair, just as a girl with short hair or a boy with short or long hair decided to have that length of hair.
"You've got long hair" is grammatically incorrect. "You have long hair" is the proper way to say it.
ROTC is not in itself a minor. However, you can minor in whatever the main field of your ROTC branch is. For example: if you complete the full curriculum for Army ROTC, you can be eligible for a Military Science Minor, or Aerospace Studies Minor with Air Force ROTC.
her hair is long is correct