the danger ahead on the railway line, he decided to go to Beijing by plane instead.
A. Having been informed of
B. Having informed of
C. To be informed of
D. Informing of
网友回答
(答案→)A. Having been informed of
B. Having informed of
C. To be informed of
D. Informing of
解析： 考察分词做状语。本句中的动词inform与后面的主语构成被动关系，故使用过去分词done表示被动，在做状语的时候done=having been done。Done更多强调被动，having been done更多强调已经完成。句义：已经被通知前面的铁路线上由危险，他决定做飞机去北京。故A正确。