A major emergency is a serious crisis event that occurs under an emergency. It includes medium and large-scale sudden natural disasters, major sudden industrial accidents and catastrophic accidents, major social disruptions and major political crises. Based on the above definitions, which of the following is situations that are not major social disruptions? ['infectious diseases and malignant poisoning.', 'Terrorist activities, ethnic conflicts, sudden disturbances in public.', 'social unrest, election crisis, coup.', 'stadium violence, detention of personnel at the railway station during the Spring Festival, crowded accidents in tourist attractions on holidays.']