图示结构位移法方程中的系数 k11＝（    ）

<span>13</span><img src、"http://hebei.ouchn.cn/pluginfile.php/61595/question/answer/585512/7/247496/image018.png" alt="" width="11" height="20">

<span>15</span><img src、"http://hebei.ouchn.cn/pluginfile.php/61595/question/answer/585512/7/247495/image018.png" alt="" width="11" height="20">

<span>8</span><img src、"http://hebei.ouchn.cn/pluginfile.php/61595/question/answer/585512/7/247494/image018.png" alt="" width="11" height="20">

3<img src、"http://hebei.ouchn.cn/pluginfile.php/61595/question/answer/585512/7/247493/image018.png" alt="" width="11" height="20">