disaster: implies an unforeseen, ruinous and often sudden misforetune that happens either through lack of foresight OR through some hostile external agency: the war proved to be a ~ for the country.


catastrophe: implies a disastrous conclusion and emphasizes finality: speculation about the ~ that befell Atlantis.


calamity: stresses a grievous misfortune involving a great personal or public loss: the father's sudden death was a ~ for the family.


cataclysm: originally refers to a deluge or geological convulsion, applies to anything that produces an upheaval or complete reversal of an existing order: the French Revolution ranks as one of the ~s of the modern era.


disaster灾难: 泛指出乎意料、毁灭性事件（可能由于缺乏预见或敌对)，catastrophe: 灾难性结果、强调终结, calamity: 哀恸不幸<--个人或群体损失，cataclysm: 原指洪水地质振动, 现指动荡和颠覆秩序。


记忆方法: 1)  首字母DCCC想成CCCD常常冲动<==招致灾难


         2)  词根记忆，回答问题，参考[词根系列] 介绍

             
             a) catastrophe和cataclysm有相同词根cata，它的意思是____，这两个词该怎样联想？


             b) disaster中的aster表示星星，请问dis的意思是____，它是259个词根中的第___个，这个词该怎样联想。


         3) 灾难的意思是可怕不幸的事件状态mean an event or situation that is or is regarded as a terrible misfortune.