(2/2)ing C having seen D to have seen 这个题为什么选择B.求详解.
问题描述：
(2/2)ing C having seen D to have seen 这个题为什么选择B.求详解.
答
原句的意思是“看到火车已开走,（我发现）等待已无意义.”
see对于主语我（在这句话里,主语I省略了）来说是主动的,所以要用-ing形式.
整句话为：Seeing that the train is gone,it is useless to wait.