All the subjects who had acute upper and lower respiratory tract infection, acute bronchitis or other lung infections were excluded from this study.

所有研究对象均除外急性上呼吸道感染、急性支气管炎及其他肺部感染等呼吸系统疾病。

youdao

All the subjects who had acute upper and lower respiratory tract infection, acute bronchitis or other lung infections were excluded from the study.

所有研究对象均除外急性上呼吸道感染、急性支气管炎及其他肺部感染等呼吸系统疾病。

youdao

In 2003, during the severe acute respiratory syndrome epidemic, 76 percent of Hong Kong residents wore simple masks, and in this case, mask use was associated with a lower incidence of SARS, as well as upper respiratory tract infections and influenza.

CNN: Commentary: Flu and your health on a plane