1.当作业未选定项目时，项目得分为灰色的N/A，选定了项目，项目得分为橘色的分数

2.当无人对作业进行互评、综评时，作业的互评、综评得分为灰色的N/A，有人进行评分则为橘色的分数
3.简化代码

app/views/bids/_homework_list.html.erb

@@ -97,12 +97,8 @@
             </td>
             <td>
               <strong>项目得分:&nbsp;
-                        <span style="color: #EC6300;">
-                            <% if homework.project != nil %>
-                               <%= project_score homework.project  %>
-                            <% else %>
-                                0.00
-                            <% end %>
+              <span style="color: <%= homework.project.nil? ? "#727272" : "#EC6300"%>;">                  
+                  <%= homework.project.nil? ? "N/A" : project_score(homework.project) %>
               </span>
               </strong>
             </td>
@@ -120,14 +116,17 @@
             </td>
             <td>
               <strong>互评得分:&nbsp;
-                          <span style="color: #EC6300;"><%= student_score_for_homework(homework)  %></span>&nbsp;&nbsp;
+                <% student_homework_score = student_score_for_homework(homework) %>
+                <span style="color:<%= student_homework_score == "0.00"? "#727272" : "#EC6300"%>;">
+                  <% score = student_homework_score == "0.00"? "N/A" : student_homework_score  %>
+                  <%= score %>
+                </span>&nbsp;&nbsp;
                 <% if is_evaluation && is_student && (!users_for_homework(homework).include? User.current)%>
                     <%= link_to "学生互评>>",homework_attach_path(homework)  %>
                 <% end %>
               </strong>
             </td>
           </tr>
-
 					<tr>
 						<td style="vertical-align: top;width: 200px;">
               <% if is_evaluation || is_teacher%>
@@ -136,7 +135,11 @@
             </td>
             <td>
               <strong>终评得分:&nbsp;
-                            <span style="color: #EC6300;"><%= score_for_homework homework  %></span>&nbsp;&nbsp;
+                <% totle_homework_score = score_for_homework(homework) %>
+                <span style="color:<%= totle_homework_score == "0.00"? "#727272" : "#EC6300"%> ;">
+                  <% score = totle_homework_score == "0.00"? "N/A" : totle_homework_score  %>
+                  <%= score %>
+                </span>&nbsp;&nbsp;
                 <% if is_teacher %>
                     <%= link_to "教师评分>>",homework_attach_path(homework)  %>
                 <% end %>