single: implies being unaccompanied or unsupported by or not combined or united with any other: a ~ example will suffice.


sole: applies to the only one that exists, acts, has power or relevance, or should be considered: my ~ reason for moving there.


unique: applies to the only one of its kind or character in existence: the medal is ~, for no duplicates were made.   (不像sole除可能表示只存在一个外，还可能表示存在多个但只考虑一个或只让一个起作用，unique则限定是只存在一个）


separate: stresses discreteness and disconnectedness or unconnectedness from every other one: a country with a ~ set of problems.     (discrete不同，是看似接近连续实际分离不同的不同，如two discrete problems are confused here把两个不同问题搞混了)


solitary: implies being both single and isolated: television was her ~ link to the outside world.    (又如solitary confinement单独关押，he is a solitary man他惯于独处)


particular: implies singular or numerical distinctness from other instances, examples, or members of a class: a ~ kind of wine.     (singular有3个意思: 1非常突出 2奇怪让人困惑 3单数，如 smile of singular sweetness非常甜美的微笑，singular feeling of impending disaster奇怪地感觉有灾难降临)       (numerical数字上的，没有译出)


single单一: 表示没有其它陪伴支持结合联合，sole唯一: 表示只有一个或存在或行动或有权或相关或应当考虑，unique独一无二: 指只存在一个，separate单独各自: 强调分离不同(discrete)，与其他断开连接(disconnected)或从未连接(unconnected)，solitary也是唯一: 除了表示唯一还表示被隔绝，particular独特: 和其他样本成员等非常不同


记忆方法: 1) 首字母SSSS UP想成四海升平<==唯一使命     升平: 太平

         2) 唯一的意思是一个而不是两个或更多mean one as distinguished from two or more or all others.首字母SSSS UP想成四海升平<==唯一使命