php怎样返回下面xml格式数据呢

Question

<xml rows="5" code="ssq" info="演示接口隐藏第1位数据)"><row expect="2016144" opencode="**,10,12,27,32,33+05" opentime="2016-12-08 21:22:23"/><row expect="2016143" opencode="**,09,23,24,25,33+13" opentime="2016-12-06 21:22:39"/><row expect="2016142" opencode="**,10,17,21,23,30+12" opentime="2016-12-04 21:22:25"/><row expect="2016141" opencode="**,13,15,17,21,24+15" opentime="2016-12-01 21:20:58"/><row expect="2016140" opencode="**,02,05,17,26,32+10" opentime="2016-11-29 21:20:54"/></xml>