string(235) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=2021%E6%B0%B4%E5%88%A9%E6%A1%88%E4%BE%8B%E9%A2%98%E8%AE%B2%E8%A7%A3 => Failed to connect to 101.89.143.195 port 38109: Connection refused"
2021水利案例题讲解
