The president promised to keep all the board members of how the negotiations were going on.
A. inform
B. informing
C. be informed
D. informed
网友回答
A. inform
B. informing
C. be informed
(答案→)D. informed
解析：考查非谓语动词.句意:董事长承诺让所有的董事会成员都知道谈判是如何进行的.过去分词作宾语补足语表示被动的动作,和被修饰词是动宾关系,结合语境可知选D.