Wearing a cloth mask over a surgical mask can “tighten the gap not covered by the surgical mask, which is often very loose,” said David Hui, a professor at the Chinese University of Hong Kong …
( read original story …)
The HongKong News
Wearing a cloth mask over a surgical mask can “tighten the gap not covered by the surgical mask, which is often very loose,” said David Hui, a professor at the Chinese University of Hong Kong …
( read original story …)