diff --git a/app/controllers/bids_controller.rb b/app/controllers/bids_controller.rb
index c0df0699c..2ad60fc29 100644
--- a/app/controllers/bids_controller.rb
+++ b/app/controllers/bids_controller.rb
@@ -410,9 +410,7 @@ class BidsController < ApplicationController
       @homework = HomeworkAttach.new
       #@homework_list = @bid.homeworks
       #增加作业按评分排序，
-      @homework_list = HomeworkAttach.find_by_sql("SELECT homework_attaches.*,
-        (SELECT AVG(stars) FROM seems_rateable_rates WHERE rateable_type = 'HomeworkAttach' AND rateable_id = homework_attaches.id) AS score
-        FROM homework_attaches WHERE bid_id = #{@bid.id} ORDER BY score DESC")
+      @homework_list = @bid.homeworks.joins(:user).includes(:rate_averages, :user, :attachments).order('seems_rateable_cached_ratings.avg DESC')
       if params[:student_id].present?
         @temp = []
         @homework_list.each do |pro|
diff --git a/app/helpers/bids_helper.rb b/app/helpers/bids_helper.rb
index 8b03d74cd..40cec6edb 100644
--- a/app/helpers/bids_helper.rb
+++ b/app/helpers/bids_helper.rb
@@ -158,7 +158,7 @@ module BidsHelper
   #当前用户是不是指定课程的学生
   def is_cur_course_student? course
   people = []
-  course.members.each do |member|
+  course.members.includes(:user, :roles).each do |member|
     if [5,10].include? member.roles.first.id
       people <<  member.user
     end
diff --git a/app/helpers/courses_helper.rb b/app/helpers/courses_helper.rb
index fb0a269e6..f16aef911 100644
--- a/app/helpers/courses_helper.rb
+++ b/app/helpers/courses_helper.rb
@@ -139,7 +139,7 @@ module CoursesHelper
   #判断制定用户是不是当前课程的老师
   def is_course_teacher user,course
     people = []
-    course.members.each do |member|
+    course.members.includes(:roles, :user).each do |member|
       role_id = member.roles.first.id
       if TeacherRoles.include? role_id
         people <<  member.user
diff --git a/app/models/user.rb b/app/models/user.rb
index d79cf11e1..689cc7b2e 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -137,7 +137,7 @@ class User < Principal
   has_one :user_extensions,:dependent => :destroy
   ## end
 
-  #default_scope -> { includes(:user_extensions, :user_score) }
+  default_scope -> { includes(:user_extensions, :user_score) }
   scope :teacher, -> {
     joins(:user_extensions).where('user_extensions.identity = ?', UserExtensions::TEACHER)
   }
diff --git a/app/views/bids/_homework_list.html.erb b/app/views/bids/_homework_list.html.erb
index 48f1c150d..d2d58753b 100644
--- a/app/views/bids/_homework_list.html.erb
+++ b/app/views/bids/_homework_list.html.erb
@@ -83,13 +83,8 @@
                         </td>
                         <td>
                           <strong>作业评分：</strong>
-                          <% stars_reates = homework.rates(:quality) %>
-                          <% sum = 0 %>
-                          <% stars_reates.each do |star_reates| %>
-                              <% sum = sum + star_reates.stars %>
-                          <% end %>
-                          <% stars_reates_count = stars_reates.count == 0 ? 1 : stars_reates.count %>
-                          <%= format("%.2f", sum * 1.0 / stars_reates_count)  %>
+
+                          <%= format("%.2f", homework.rate_averages.first.try(:avg).to_i )  %>
                         </td>
 						<td valign="top" align="right">
 							<% if Time.parse(@bid.deadline.to_s) < Time.parse(homework.created_at.to_s) %>
@@ -100,7 +95,7 @@
 					<tr>
 						<td valign="top">&nbsp;
                             <% if User.current.member_of?(@bid.courses.first) %>
-                                <strong><%= l(:label_bidding_user_studentcode) %>&nbsp; ：&nbsp;<%= homework.user.user_extensions.student_id%></strong>
+                                <strong><%= l(:label_bidding_user_studentcode) %>&nbsp; ：&nbsp;<%= homework.user.student_id%></strong>
                             <% end %>
 						</td>
                         <td>
diff --git a/app/views/layouts/base_homework.html.erb b/app/views/layouts/base_homework.html.erb
index 81a8b0861..8c108ba22 100644
--- a/app/views/layouts/base_homework.html.erb
+++ b/app/views/layouts/base_homework.html.erb
@@ -18,8 +18,8 @@
 		<%= yield :header_tags -%>
 	</head>
 	<body class="<%= h body_css_classes %>">
-    <% project = @bid.courses.first %>
-    <% course = Course.find_by_extra(project.identifier) %>
+    <% project = @bid.courses.includes(:course_extra).first %>
+    <% course = project.course_extra %>
 		<div id="wrapper">
 			<div id="wrapper2">
 				<div id="wrapper3">