from the top of the hill, the city is of round shape with a flowing river through it.
A. Seeing
B. To be seen
C. Seen
D. To be seeing
网友回答
A. Seeing
B. To be seen
(答案→)C. Seen
D. To be seeing
解析： 考查非谓语动词，the city与see之间是动宾关系，故用过去分词，句意：这座城市从山顶上被看的话，它的形状是圆的流水流经这里。故选C。