I can't. The four certificates are familiarity and basic safety training certificate, lifeboat and rescue boat training proficiency certificate, advanced fire fighting training certificate and first aid training proficiency certificate. The four certificates/kloc-expire in 0/2 days and cannot be boarded. After boarding, you will be unable to disembark because of incomplete documents. The "four certificates" include the "four" subjects in the "basic safety training" course: personal survival, fire prevention and extinguishing, basic first aid, personal safety and social responsibility, and are the legal certificates that every sailor must hold.