When he looked up, he suddenly found himself by a group of teenagers,A.to be surrounded;B.surrounded;C.be surrounded;D.having been surrounded;
网友回答
B解析考查过去分词作宾补，此题考查的结构是find sth/sb done,句意：当他抬头的时候，他突然发现他自己被一群青少年包围着。be surrounded by被什么包围，在这里surrounded做宾补。所以选B。