When you are outside, consider using a face mask that can filter out PM2.5 particles.

当你在外边时，考虑用一个能够过滤PM 2.5颗粒的口罩。

youdao

When you are outside, consider using a face mask that can filter out PM2.5 particles.

当你在外边时，考虑用一个能够过滤PM 2.5颗粒的口罩。

youdao