有病當然要戴口罩，是為了防止傳染給別人，但沒病一樣要戴，是為了防止吸入

有病當然要戴口罩，是為了防止傳染給別人，但沒病一樣要戴，是為了防止吸入別人的飛沫

結果 (英文) 1:

Of course, sick to wear masks, to prevent transmission to others, but not sick, like to wear, is to prevent inhalation of droplets others

結果 (英文) 3:

If you are ill, of course, you need to wear a mask to prevent infection to others. If you are not ill, you need to wear a mask to prevent inhalation of other people's droplets