string(249) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%B8%80%E5%BB%BA%E6%9C%BA%E7%94%B5%E4%B8%BB%E8%A6%81%E5%AD%A6%E4%BB%80%E4%B9%88 => Failed to connect to 101.89.117.144 port 38208: Connection refused"
一建机电主要学什么
