(1) It is the responsibility of       to do sth.    

    【分析】注意，从形式上看该句子很像强调句型，而实际上并非如此，因为句中it是形式主语，动词不定式作实际主语。   

    It is the responsibility of every citizen in our society to do his utmost to protect the environment.    

    (2) It is the       , I suppose, that havehas given rise to       .    

    【分析】该强调句型强调句子主语，I suppose作为插入语。这是一个很好掌握的四级长句，在作文中需要分析原因时，可以用它阐述自己的看法。   

    It is the tighter job market, I suppose, that has given rise to the increase in the number of unemployed college students in China.    

    (3) It is only when       that       .   

    【分析】强调句型强调when引导时间从句。   

    It is only when you nearly lose someone that you become fully conscious of how much you value him.