感觉数学好难啊！！<img class="BDE_Image" changedsize="false" height="25" width="25" src="http://imo.baidu.com/static/images/emotion/8.gif"><img class="BDE_Image" changedsize="false" height="25" width="25" src="http://imo.baidu.com/static/images/emotion/8.gif">
