poison: is applicable to any deadly or noxious substance (such as strychnine, arsenic, or carbon monoxide) or to anything felt to have a comparable effect: a friendship destroyed by the ~ of jealousy.      (noxious有毒有害poisonous or harmful，如many household products give off noxious fumes很多家用产品释放有害气体，这个词还表示让人讨厌，如their behavior was noxious他们的行为令人生厌)          strychnine马钱子碱，arsenic砒霜  CO一氧化碳


venom: applies to a poison-containing fluid secreted by an animal such as snake, bee, or spider and injected into another animal in defensive or predatory action; it may also imply a malignant hostility: a review full of ~.   （secrete分泌，形近词excrete排泄）   malignant恶毒的: 对人有很深的仇恨，贬义。


virus: applies to what is felt to have a corrupting quality poisonous to mind and spirit: the ~ of apathy; or to a submicroscopic agent of infection working with insidious deadliness or destructiveness: the ~ that caused AIDS.    (corrupt有两个意思，1 道德腐败，2 使不再健康纯洁有效完整等，即损坏某一方面，这里用的第二个意思)  (insidious隐伏潜藏，难以察觉，destructive毁灭性)


toxin: denotes a complex organic poison produced by a living organism, especially a bacterial or virus: the ~s causing the plague; it may also imply an insidious undermining effect like that of a bacterial toxin: a nation undermined by the ~ of ethnic divisiveness.


bane: may apply to any cause of ruin, destruction, or tribulation: the ~ of his existence.    （ruin废墟,完全损坏，如圆明园废墟Yuanmingyuan Ruins Park圆明园遗址公园） （tribulation苦难=suffering and difficulty，如life is full of tribulations生活充满苦难）  (又如avarice is the bane to happiness贪婪是毁灭幸福的祸根)  


poison毒: 任何致命或有害物质，或效果类似的事物，venom毒液: 表示动物分泌的含毒液体,或表示恶毒敌意，virus病毒: 表示损害思想心灵的事物，或表示剧毒传染物(agent of infection)，toxin毒素: 指有机体产生的复杂有机毒药（如由细菌病毒产生的），还表示暗中破坏（undermine暗中破坏）的效果类似的事物，bane祸根，不尽烦恼: 导致毁灭苦难的任何原因


记忆方法: 1）首字母PVVTB，把两个V看作W变成WBPT我不碰它<==毒药


         2）毒药的意思是会导致死亡或损害的物质mean material that when present in or introduced into a living organism produces a deadly or injurious effect.