When we buy a mask, there are many directions to choose from, below maysino lists some details of the selection points.

If you donate blood frequently, if you pay attention, you will find the blood bag is different. At present, blood bags for donating whole blood in China are mainly divided into three types: 200, 300, and 400 ml.

In order to make the production process of epidemic prevention materials more standardized and consolidate the foundation of the first line of defense for epidemic prevention work,

The pneumonia epidemic infected by the new coronavirus has spread, and the mask has become the "first protective wall".