string(249) "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%BF%85%E8%80%83%E7%9F%A5%E8%AF%86%E7%82%B9 => Failed to connect to 101.89.159.206 port 38087: Connection refused"
二建机电必考知识点
