string(255) "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%E7%9A%84%E7%94%A8%E9%80%94%E6%98%AF%E4%BB%80%E4%B9%88 => Failed to connect to 14.18.46.51 port 38044: Connection refused"
基尼系数的用途是什么
