ObjectiveTo explore the relationships between performance record and sleep status of urban middle school students, and to search for difference of sleep status between the good students and the bad.

目的探讨城市中学生睡眠状况与学习成绩的关系，及优差生之间睡眠状况有无差异。

youdao

ObjectiveTo explore the relationships between performance record and sleep status of urban middle school students, and to search for difference of sleep status between the good students and the bad.

目的探讨城市中学生睡眠状况与学习成绩的关系，及优差生之间睡眠状况有无差异。

youdao