septinary number

例句：

1. 1.The number of students in the class is septinary.
   班上学生人数是七分之一。
2. 2.She was born septinary, and she has lived for eighty-eight years.
   她出生时是七分之一，已经活了八十八年。
3. 3.The septinary age is a milestone in human life.
   七分之一的年龄是人类生活中的一个里程碑。