string(262) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=2021%E4%BA%8C%E5%BB%BA%E6%9C%BA%E7%94%B5%E6%95%99%E6%9D%90%E5%8F%98%E5%8A%A8%E5%A4%A7%E5%90%97 => Failed to connect to 101.89.143.195 port 38109: Connection refused"
2021二建机电教材变动大吗
