string(258) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%BB%8F%E6%B5%8E%E6%89%8B%E6%AE%B5%E7%9A%84%E5%AE%9A%E4%B9%89%E6%98%AF%E4%BB%80%E4%B9%88 => Failed to connect to 101.89.166.210 port 38089: Connection refused"
经济手段的定义是什么
