Often,we just walk around the town center,seeing as many our

Often,we just walk around the town center,seeing as many our friends as we can
请问为什么see加ing

seeing as many our friends as we can是做主句“we just walk around the town center”中主语“we”的伴随状语.
此种情况的发生是由于主句中已存在一个充当谓语的动词“walk”,在非复合句（如宾语从等）中,一句话中只可出现一个谓语动词,故要再出现一个动词必将它改成状语.
并且,可以看到,see后面加的是ing而非改成它的过去分词seen就是因为seeing as many our friends as we can与主句主语的关系是主动关系.
P.S.非复合句（如宾语从等）中,一句话中只可出现一个谓语动词,故要再出现一个动词必将它改成状语.这时,如果这个动词与主句主语为主动关系,则改成动词的现在分词形式；如为被动关系,则改为动词的过去分词形式.

这下我知道了