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中國工程院院士孫寶國為學員們講授食品安全知識

2015年06月24日 16:04   來源：   

中國工程院院士、北京工商大學校長孫寶國為學員們講授食品安全知識。中國經濟網記者王澤彪/攝

（責任編輯：韓肖）

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