string(240) "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%E6%9C%BA%E7%94%B5%E5%AE%9E%E5%8A%A1%E8%AE%B2%E4%B9%89 => Failed to connect to 101.89.143.195 port 38205: Connection refused"
二建机电实务讲义
