The basic features of infectious disease are A: There are infectivity, pathogen, epidemic, immunity. B: There are infectivity, patients, immunity, epidemic. C: There are source of infection, route of transmission, susceptibility, immunity. D: There are infectivity, epidemic, endemic, relapse. E: There are pathogen, reinfection, epidemic, immunity.

危险废物具有（）等特性。 A: 毒性（Toxicity, T） B: 易燃性（Ignitability, I） C: 腐蚀性（Corrosivity, C） D: 反应性（Reactivity, R） E: 感染性（Infectivity, In）