目的：研究不同软硬度床褥对睡眠质量的影响。

Objective: To investigate the various effects of the mattresses with different firmness on sleep quality.

youdao

目的：研究不同软硬度床褥对睡眠质量的影响。

Objective: To investigate the various effects of the mattresses with different firmness on sleep quality.

youdao