Age at menarche的用法和样例：
- Objective:To analyze the correlative factors of age at menarche of Guangxi.
- The association was not explained by childhood lung function or age at menarche.
- Indeed, two teams found that several other genes linked to height also predict age at menarche.
- Not only the genetic factors but also the uterine environment and the development in childhood are related to the age at menarche.
- Yet another study showed that LBP during pregnancy was not related to mean age at menarche or irregular menstrual cycle but was associated with amenorrhea.
- There was no significant difference in age at menarche between menstruating AIS and non-AIS girls, though an inverse correlation was observed between leptin and the age at menarche.