1.  Two years.  A secondary school shall include not fewer than 2 consecutive grades from grades 9 to 12.  

2.  Junior high school or middle school.  A junior high school or middle school is a school that maintains a diversified program of studies of 2 or more consecutive grades from grades 6 to 9, which meets basic school approval and applicable curriculum requirements. A junior high school or middle school may be maintained in connection with or as part of an approved secondary school.