string(249) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%B8%AD%E7%BA%A7%E9%87%8D%E7%82%B9%E7%9F%A5%E8%AF%86%E7%82%B9%E5%BD%92%E7%BA%B3 => Failed to connect to 101.89.143.195 port 38175: Connection refused"
中级重点知识点归纳
