People must wear masks scientifically for the following reasons: First, scientific and correct wearing of masks can effectively block pathogenic bacteria, such as disease-causing bacteria and viruses. If you wear a mask, there is no science and correct wear, such as mouth, nose leakage in the outside of the mask, it does not play a protective role, wear a mask and no mask effect, the air in the pathogenic bacteria will enter the human body with breathing. Second, wear a mask must wear a suitable mask, such as want to protect the new crown virus, this time to wear surgical masks and PM2.5 masks can be. If you want to protect against haze and dust, you must choose a professional mask that can protect against dust particles, such as a mask that can protect against PM2.5, to be able to play an effective protective role. Third, wear a mask for a long time, there may be chest tightness, shortness of breath, poor breathing and other problems, especially some children, lung capacity is relatively small, cardiopulmonary function is not mature, if long-term wear a mask, there may be breathing difficulties, oxygen supply problems, such as primary and secondary school students wearing masks, running and other sports activities, there is a risk of fainting accidents For example, students in primary and secondary schools may faint when wearing masks for sports activities such as running, so they must wear masks scientifically.