作图示静定梁FRB的影响线（5分）   解：作影响线如（    ）示。

<img src、"http://hebei.ouchn.cn/pluginfile.php/61596/question/answer/585572/25/247874/image073a.png" alt="" width="271" height="56">

<img src、"http://hebei.ouchn.cn/pluginfile.php/61596/question/answer/585572/25/247875/image073b.png" alt="" width="273" height="79">

<img src、"http://hebei.ouchn.cn/pluginfile.php/61596/question/answer/585572/25/247876/image073c.png" alt="" width="271" height="102">

<img src、"http://hebei.ouchn.cn/pluginfile.php/61596/question/answer/585572/25/247877/image073d.png" alt="" width="273" height="63">