string(262) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%A6%82%E4%BD%95%E7%90%86%E8%A7%A3kol%E5%92%8Ckoc%E8%BF%99%E4%B8%A4%E4%B8%AA%E6%A6%82%E5%BF%B5 => Failed to connect to 14.18.117.71 port 38220: Connection refused"
如何理解kol和koc这两个概念
