研究人员说，在这项新研究之前，人们对于在飞机上直接感染常见的呼吸道病毒，如流感或普通感冒的风险知之甚少。

Prior to the new study, little was known about the risks of getting directly infected by common respiratory viruses, such as the flu or common cold, on an airplane, the researchers said.

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在这项新研究中，有一个关键因素值得注意。

There are key variables to note in the new study.

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在这项新研究中，有25毫克，每天似乎是有效的。

In the new study, 25 mg per day appeared to be effective.

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