cool: may imply calmness, deliberateness, or dispassionateness: kept a ~ head during the emergency.     (dispassionate不受情绪影响，能够冷静判断，如a dispassionate summation of facts冷静地总结事实)       (cool在字典里有16个意思，分两类1冷静 2好,如有能力数量多时髦等)


composed: implies freedom from agitation as a result of self-discipline or a sedate disposition: the ~ pianist gave a flawless concert.  (discipline纪律训练管教，根本意思是控制) （sedate和本词composed互释，表示composed and serious镇定而严肃，如amid the frenzy of activity the bride remained sedate新娘保持镇定）


collected: implies a concentration of the mind or spirit that eliminates or overcomes distraction: even in heated debate she remains very ~.


unruffled: suggests apparent serenity and poise in the face of setbacks or in the midst of excitement: his mother remained ~ during the wedding.    (poise自信自如=self-possession,ease如the poise of one who has been officiating all his life一个终身任职的官员的镇定自如)


imperturbable: implies a temperament that is cool or assured even under severe provocation: a guest speaker who maintained an air of ~ civility.         俞老师曾说过imperturbable这种性格非常好


nonchalant: stresses an easy coolness of manner or casualness that suggests indifference or unconcern: ~ as ever, she ignored the crying baby.     (cool这里是表示冷淡)


cool冷静: 表示平静思考无情绪，composed镇定: 不紧张，来自自制或性格，collected专注: 集中精力排除干扰，unruffled镇定: 平静自如地面对挫折或喧闹，imperturbable还是镇定: 即使受到严重挑衅也能保持冷静自信的性格，nonchalant冷淡漠视: 表现得冷淡随意、无所谓不关注


记忆方法: 1) 首字母CCCUIN中CCC想成很酷(cool)，NIU想成牛，很酷的牛<==冷静的动物

         2) 冷静的意思是不紧张激动mean actually or apparently free from agitation or excitement.首字母CCCUIN中CCC想成很酷(cool)，NIU想成牛，很酷的牛<==冷静的动物       (agitation紧张也是一种激动,即nervous excitement紧张的激动，所以一般agitate说成紧张，excitement说成激动)