string(256) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%BA%8C%E5%BB%BA%E5%AF%BC%E5%AD%A6%E8%AF%BE%E6%9C%89%E5%BF%85%E8%A6%81%E7%9C%8B%E5%90%97 => Failed to connect to 14.18.117.71 port 38220: Connection refused"
二建导学课有必要看吗
