Complex sentence: Often, each college or university sets their own score thresholds for determining whether a student must enroll in remedial courses, and students are required to enroll in remedial courses before advancing to a college level course in that subject.
Split into simpler sentences: Often, each college or university sets their own score thresholds for determining whether a student must enroll in remedial courses. Students are required to enroll in remedial courses before advancing to a college level course in that subject.