string(250) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=idc%E9%A1%B9%E7%9B%AE%E5%8F%82%E8%80%83%E6%96%87%E7%8C%AE%E6%98%AF%E4%BB%80%E4%B9%88 => Failed to connect to 14.18.117.71 port 38220: Connection refused"
idc项目参考文献是什么
