string(265) "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%E8%80%83%E8%AF%95%E5%89%8D%E9%9C%80%E8%A6%81%E5%87%86%E5%A4%87%E4%BB%80%E4%B9%88 => Failed to connect to 14.18.117.71 port 38133: Connection refused"
二建考试前需要准备什么
