string(284) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%9F%BA%E5%B0%BC%E7%B3%BB%E6%95%B0%E8%AF%B4%E6%98%8E%E4%BA%86%E4%B8%80%E4%B8%AA%E4%BB%80%E4%B9%88%E7%8E%B0%E8%B1%A1 => Failed to connect to 101.91.112.32 port 38195: Connection refused"
基尼系数说明了一个什么现象
