The suspects who carried out the terrorist attacks will not be marked on their faces, but there will be some unusual behaviors that can cause our vigilance, such as: (1) panic, abnormal behavior and words; (2) dress, carry items and their identity Obviously inconsistent, or uncoordinated with the season; (3) impersonate an acquaintance or fake attentive; (4) during the inspection process, urge the inspection or attitude of being arrogant, unwilling to accept the inspection; (5) frequent entry and exit of large-scale activities; (6) Repeated appearances near the security zone; (7) Suspected persons suspected of being notified by the public security department. Conventional means: (1) Explosion: bomb explosion, car bomb explosion, suicide bomb explosion, etc .; (2) Arson: on vehicles, such as buses, subways, passenger ships; shopping malls, high-rise buildings, entertainment venues, etc .; (3) Shooting: shooting with a pistol, shooting with a standard rifle or submachine gun, etc .; (4) Hijacking: hijacking people, hijacking cars, ships, planes, etc .; Unconventional means: biochemical terrorist attacks (1) Nuclear and radiation terrorist attacks: through nuclear explosions or the spread of radioactive materials, causing environmental pollution or exposing personnel to radiation exposure; (2) Bioterrorism attack: Harmful organisms or products of harmful organisms are used to invade people, crops, and livestock. For example, the anthrax mail incident occurred after the 9.11 incident in the United States; (3) Chemical terrorist attacks: the use of toxic and harmful chemical substances against people, important urban infrastructure, food and drinking water, etc. Such as the Tokyo subway sarin gas attack; (4) Internet terrorist attacks: use the Internet to spread terrorist attacks, organize terrorist activities, attack computer programs and information systems, etc. 3Pc Ball Valves , 3Pc Ball Valve ,Stainless Steel 3Pc Ball Valve,3Pc Ball Valve With Extended Pipe WENZHOU DIYE VALVE&FITTINGS CO.,LTD , https://www.diye-valve.com