正常对照组来自重庆市主城区健康志愿者45例。

And 45 healthy volunteers were used as control group.

youdao

以20名健康志愿者作为正常对照组。

Another 20 healthy volunteers were served as control group.

youdao

以20名健康志愿者作为正常对照组。

Another 20 healthy volunteers were served as control group.

youdao