string(242) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=po%E6%98%AF%E4%BB%80%E4%B9%88%E8%8B%B1%E6%96%87%E7%9A%84%E7%BC%A9%E5%86%99 => Failed to connect to 125.88.227.171 port 38062: Connection refused"
po是什么英文的缩写
