Complex sentence: The school has two campuses: one for the lower/middle school, and one for the upper school and enrolls 1,100 students from Junior Kindergarten through Twelfth Grade who exhibit high standards of character and conduct and the potential for achieving success in a demanding academic program.
Split into simpler sentences: The school has two campuses: one for the lower/middle school, and one for the upper school. It enrolls 1,100 students from Junior Kindergarten through Twelfth Grade who exhibit high standards of character and conduct and the potential for achieving success in a demanding academic program.