anchor.diff:        <div class="col-sm-9">
           <div class="input-group">
             <div class="input-group-addon"><span class="glyphicon glyphicon-arrow-right"></span></div>
  -          <%= f.text_field :course_time, class: 'form-control', placeholder: "输入课时学分" %>
  +          <%= f.text_field :course_time, class: 'form-control', placeholder: "输入上课时间" %>
           </div>
         </div>
       </div>
  
positive.code:       <div class="col-sm-9">
          <div class="input-group">
            <div class="input-group-addon"><span class="glyphicon glyphicon-arrow-right"></span></div>
            <%= f.text_field :course_week, class: 'form-control', placeholder: "输入课时学分" %>
          </div>
        </div>
      </div>
  
negative.code:         <div class="input-group">
            <div class="input-group-addon"><span class="glyphicon glyphicon-arrow-right"></span></div>
            <%= f.text_field :name, class: 'form-control', placeholder: "输入课程名" %>
          </div>
        </div>
      </div>
          <div class="form-group">
        <%= f.label "课程编号", class: 'col-sm-3 control-label' %>
        <div class="col-sm-9">
          <div class="input-group">
            <div class="input-group-addon"><span class="glyphicon glyphicon-arrow-right"></span></div>
            <%= f.text_field :course_code, class: 'form-control', placeholder: "输入课程编号" %>
          </div>
        </div>
      </div>
  