diff --git a/app/controllers/exercise_controller.rb b/app/controllers/exercise_controller.rb
index 73da3b9c4..3ed5886e7 100644
--- a/app/controllers/exercise_controller.rb
+++ b/app/controllers/exercise_controller.rb
@@ -359,7 +359,7 @@ class ExerciseController < ApplicationController
     if @exercise.end_time <= Time.now
       @course.student.each do |student|
         if ExerciseUser.where("user_id = ? && exercise_id = ?",student.student_id,@exercise.id).empty?
-          ExerciseUser.create(:user_id => student.student_id, :exercise_id => @exercise.id, :start_at => @exercise.end_time, :status => false,:score=>0)
+          ExerciseUser.create(:user_id => student.student_id, :exercise_id => @exercise.id, :start_at => @exercise.end_time, :status => true,:score=>0)
         end
 
         s_score = calculate_student_score(@exercise, student.student)
@@ -577,15 +577,15 @@ class ExerciseController < ApplicationController
       standard_answer = get_user_standard_answer(question, user)
       unless answer.empty?
         # 问答题有多个答案
-        if question.question_type == 3
+        if question.question_type == 3 && !standard_answer.empty?
           if standard_answer.include?(answer.first.answer_text)
             score1 = score1+ question.question_score unless question.question_score.nil?
           end
-        elsif question.question_type == 1
+        elsif question.question_type == 1 && !standard_answer.nil?
           if answer.first.exercise_choice.choice_position == standard_answer.exercise_choice_id
             score2 = score2 + question.question_score unless question.question_score.nil?
           end
-        else
+        elsif question.question_type == 2 && !standard_answer.nil?
           arr = get_mulscore(question, user)
           if arr.to_i == standard_answer.exercise_choice_id
             score3 = score3 + question.question_score unless question.question_score.nil?
diff --git a/app/views/exercise/_exercise_teacher.html.erb b/app/views/exercise/_exercise_teacher.html.erb
index 24687d28b..586c033a1 100644
--- a/app/views/exercise/_exercise_teacher.html.erb
+++ b/app/views/exercise/_exercise_teacher.html.erb
@@ -32,7 +32,7 @@
               <div>
                 <div class="testEditTitle"> 第<%= list_index+1%>题：<%= exercise_question.question_title %>&nbsp;&nbsp;(<%= exercise_question.question_score %>分)
                   <br />
-                  标准答案：<%= convert_to_char(exercise_question.exercise_standard_answers.first.exercise_choice_id.to_s) %>
+                  标准答案：<%= convert_to_char(exercise_question.exercise_standard_answers.first.exercise_choice_id.to_s)  if exercise_question.exercise_standard_answers.first  %>
                 </div>
                 <div class="cl"></div>
                 <div class="ur_inputs">
@@ -64,7 +64,7 @@
               <div>
                 <div class="testEditTitle"> 第<%= list_index+1%>题：<%= exercise_question.question_title %>&nbsp;&nbsp;(<%= exercise_question.question_score %>分)
                   <br />
-                  标准答案：<%= convert_to_char(exercise_question.exercise_standard_answers.first.exercise_choice_id.to_s) %>
+                  标准答案：<%= convert_to_char(exercise_question.exercise_standard_answers.first.exercise_choice_id.to_s)  if exercise_question.exercise_standard_answers.first%>
                 </div>
                 <div class="cl"></div>
                 <div class="ur_inputs">
diff --git a/db/schema.rb b/db/schema.rb
index 9926f2876..51020f45d 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20151215105425) do
+ActiveRecord::Schema.define(:version => 20151215112107) do
 
   create_table "activities", :force => true do |t|
     t.integer  "act_id",                                  :null => false
@@ -1161,6 +1161,7 @@ ActiveRecord::Schema.define(:version => 20151215105425) do
     t.datetime "updated_at",                         :null => false
     t.boolean  "locked",          :default => false
     t.integer  "sticky",          :default => 0
+    t.integer  "org_subfield_id"
   end
 
   create_table "org_member_roles", :force => true do |t|
@@ -1187,6 +1188,7 @@ ActiveRecord::Schema.define(:version => 20151215105425) do
     t.string   "name"
     t.datetime "created_at",      :null => false
     t.datetime "updated_at",      :null => false
+    t.string   "field_type"
   end
 
   create_table "organizations", :force => true do |t|