string(292) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%B0%86%E8%A1%A8%E6%A0%BC%E6%A0%87%E9%A2%98%E5%8D%95%E5%85%83%E6%A0%BC%E5%90%88%E5%B9%B6%E5%B1%85%E4%B8%AD%E6%AD%A5%E9%AA%A4 => Failed to connect to 14.18.117.71 port 38164: Connection refused"
将表格标题单元格合并居中步骤
