string(265) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%9F%AD%E8%B7%AF%E4%B8%8E%E5%92%8C%E7%9F%AD%E8%B7%AF%E6%88%96%E7%9A%84%E4%BC%98%E5%85%88%E7%BA%A7 => Failed to connect to 14.18.117.71 port 38069: Connection refused"
短路与和短路或的优先级
