And about 10 to 30 percent of all the upper respiratory infections are caused by corona viruses.

大约10%到30%的上呼吸道感染是由冠状病毒引起的。

I mean, if someone who whenever they get an upper respiratory infection really dramatically exacerbates their asthma.

如果某人受到上呼吸道感染，确实会大大加剧他们的哮喘。

Three of the four had had a recent upper respiratory infection, and two had the Epstein-Barr virus.

四名孩子中有三名最近患有上呼吸道感染，两名携带 EB 病毒。