we should use masks to protect our health. There are many types of masks for use. The Center for Health Protection of the Department of Health provides a reference link for the correct use of masks:,  https://www.chp.gov.hk/files/pdf/use_mask_properly_chi.pdf  
 The Center for Health Protection of the Department of Health provides a YouTube reference link for the correct use of masks:,  https://www.youtube.com/watch?v=BZ8dFHOE2 -4&feature=youtu.be

Please stick to the following picture to watch more information.