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 or poise in the face of setbacks or in the midst of excitement: his mother remained ~ during the wedding.    (poise掌控自信自如=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.          老俞好像说过这种性格非常好？


nonchalant: stresses an easy coolness of manner or casualness that suggests indifference or unconcern: ~ as ever, she ignored the crying baby.


cool冷静: 表示平静思虑不受情绪影响(calm,deliberate,dispassionate)，composed镇定: 不紧张, 来自自我控制或镇定性格(sedate见词条)，collected专注: 集中精力排除干扰，unruffled镇定: 面对自身挫败或他人激动能保持平静自如，imperturbable还是镇定: 表示即使面对严重挑衅也能保持冷静自信的性情(temperament)，nonchalant不在乎: 表现得轻松冷淡(cool这里是冷淡),看上去无所谓不关注。


记忆方法: 1）首字母CCCUIN: CCC想成很酷，NIU想成牛，酷牛<==又冷静又牛的动物


         2）冷静的意思是不紧张激动mean actually or apparently free from agitation or excitement.       (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)