string(256) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%99%BE%E5%88%86%E6%95%B0%E5%BA%94%E7%94%A8%E9%A2%98%E5%88%A9%E6%B6%A6%E9%97%AE%E9%A2%98 => Failed to connect to 14.18.117.71 port 38093: Connection refused"
百分数应用题利润问题
