diff --git a/app/controllers/attachments_controller.rb b/app/controllers/attachments_controller.rb
index a6c74818c..a85937315 100644
--- a/app/controllers/attachments_controller.rb
+++ b/app/controllers/attachments_controller.rb
@@ -162,28 +162,30 @@ class AttachmentsController < ApplicationController
   def attachment_candown
     unless current_user.admin? || current_user.business?
       candown = true
-      if @file.container && current_user.logged?
-        # 课堂资源、作业、毕设相关资源的权限判断
-        if @file.container.is_a?(Course)
-          course = @file.container
-          candown = current_user.member_of_course?(course) || @file.is_public == 1
-        elsif @file.container.is_a?(HomeworkCommon) || @file.container.is_a?(GraduationTask) || @file.container.is_a?(GraduationTopic)
-          course = @file.container&.course
-          candown = current_user.member_of_course?(course)
-        elsif @file.container.is_a?(StudentWork)
-          course = @file.container&.homework_common&.course
-          candown = current_user.member_of_course?(course)
-        elsif @file.container.is_a?(StudentWorksScore)
-          course = @file.container&.student_work&.homework_common&.course
-          candown = current_user.member_of_course?(course)
-        elsif @file.container.is_a?(GraduationWork)
-          course = @file.container&.graduation_task&.course
-          candown = current_user.member_of_course?(course)
-        elsif @file.container.is_a?(GraduationWorkScore)
-          course = @file.container&.graduation_work&.graduation_task&.course
-          candown = current_user.member_of_course?(course)
+      unless params[:type] == 'history'
+        if @file.container && current_user.logged?
+          # 课堂资源、作业、毕设相关资源的权限判断
+          if @file.container.is_a?(Course)
+            course = @file.container
+            candown = current_user.member_of_course?(course) || @file.is_public == 1
+          elsif @file.container.is_a?(HomeworkCommon) || @file.container.is_a?(GraduationTask) || @file.container.is_a?(GraduationTopic)
+            course = @file.container&.course
+            candown = current_user.member_of_course?(course)
+          elsif @file.container.is_a?(StudentWork)
+            course = @file.container&.homework_common&.course
+            candown = current_user.member_of_course?(course)
+          elsif @file.container.is_a?(StudentWorksScore)
+            course = @file.container&.student_work&.homework_common&.course
+            candown = current_user.member_of_course?(course)
+          elsif @file.container.is_a?(GraduationWork)
+            course = @file.container&.graduation_task&.course
+            candown = current_user.member_of_course?(course)
+          elsif @file.container.is_a?(GraduationWorkScore)
+            course = @file.container&.graduation_work&.graduation_task&.course
+            candown = current_user.member_of_course?(course)
+          end
+          tip_exception(403, "您没有权限进入") if course.present? && !candown
         end
-        tip_exception(403, "您没有权限进入") if course.present? && !candown
       end
     end
   end
diff --git a/app/controllers/courses_controller.rb b/app/controllers/courses_controller.rb
index 106ba3dd4..aaf24eadb 100644
--- a/app/controllers/courses_controller.rb
+++ b/app/controllers/courses_controller.rb
@@ -1129,7 +1129,7 @@ class CoursesController < ApplicationController
 
   def validate_course_name
     tip_exception("课堂名称不能为空！") if params[:course][:name].blank?
-    if params[:subject_id].blank? || (@course && @course.subject.blank?)
+    if params[:subject_id].blank? && @course.blank? || (@course && @course.subject.blank?)
       tip_exception("课程名称不能为空！") if params[:course_list_name].blank?
       tip_exception("课堂名称应以课程名称开头命名") unless params[:course][:name].index(params[:course_list_name]) &&
         params[:course][:name].index(params[:course_list_name]) == 0
diff --git a/app/controllers/exercises_controller.rb b/app/controllers/exercises_controller.rb
index 781ede214..c9162448b 100644
--- a/app/controllers/exercises_controller.rb
+++ b/app/controllers/exercises_controller.rb
@@ -1566,15 +1566,22 @@ class ExercisesController < ApplicationController
 
   def check_user_id_start_answer #判断用户在开始答题时，是否有用户id传入,如果为老师，则id必需，否则为当前用户的id
     user_login = params[:login]
-    # exercise_current_user_id = params[:user_id]
     if user_login.blank? && @user_course_identity < Course::STUDENT  #id不存在，且当前为老师/管理员等
       normal_status(-1,"请输入学生登陆名！")
     else
-      @ex_answerer = User.find_by(login: user_login) #回答者
+      if @user_course_identity < Course::STUDENT || @exercise.score_open
+        @ex_answerer = user_login.blank? ? current_user : User.find_by(login: user_login)
+      else
+        @ex_answerer = current_user
+      end
+
       if @ex_answerer.blank?
         normal_status(404,"答题用户不存在")
+      elsif @user_course_identity > Course::STUDENT && !@exercise.is_public
+        normal_status(403,"非公开试卷")
       else
-        @exercise_current_user_id = @ex_answerer.id || current_user.id
+        # @exercise_current_user_id = @ex_answerer.id || current_user.id
+        @exercise_current_user_id = @ex_answerer.id
       end
     end
   end
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index e6f2e1720..099d45406 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -258,7 +258,7 @@ module ApplicationHelper
   end
 
   def download_url attachment
-    attachment_path(attachment).gsub("/api","")
+    attachment_path(attachment)
   end
 
   # 耗时：天、小时、分、秒
diff --git a/app/models/homework_common.rb b/app/models/homework_common.rb
index 112fc523b..f198a7143 100644
--- a/app/models/homework_common.rb
+++ b/app/models/homework_common.rb
@@ -36,7 +36,7 @@ class HomeworkCommon < ApplicationRecord
 
   validates :name, length: { maximum: 60 }
   validates :description, length: { maximum: 15000 }
-  validates :reference_answer, length: { maximum: 5000 }
+  validates :reference_answer, length: { maximum: 15000 }
 
   # after_update :update_activity
   before_destroy :update_homework_bank_quotes
diff --git a/app/views/attachment_histories/_attachment_history.json.jbuilder b/app/views/attachment_histories/_attachment_history.json.jbuilder
index afb359e08..285aced42 100644
--- a/app/views/attachment_histories/_attachment_history.json.jbuilder
+++ b/app/views/attachment_histories/_attachment_history.json.jbuilder
@@ -8,3 +8,4 @@ json.downloads_count attachment.downloads_count
 json.created_on attachment.created_on
 json.url attachment_path(attachment, type: 'history').gsub("/api","")
 json.is_pdf attachment.is_history_pdf?
+json.attachment_id attachment.attachment_id
diff --git a/app/views/courses/settings.json.jbuilder b/app/views/courses/settings.json.jbuilder
index be4470a66..97083d5f9 100644
--- a/app/views/courses/settings.json.jbuilder
+++ b/app/views/courses/settings.json.jbuilder
@@ -5,6 +5,7 @@ json.course_id @course.id
 json.school @course.school&.name
 json.class_period @course.class_period
 json.credit @course.credit
+json.start_date @course.start_date
 json.end_date @course.end_date
 json.is_public @course.is_public
 json.course_module_types @course.course_modules.where(hidden: 0).pluck(:module_type)
diff --git a/app/views/files/histories.json.jbuilder b/app/views/files/histories.json.jbuilder
index 7039752e7..ed322bb17 100644
--- a/app/views/files/histories.json.jbuilder
+++ b/app/views/files/histories.json.jbuilder
@@ -1,3 +1,9 @@
 
-json.partial! 'attachments/attachment_small', attachment: @file
+# json.partial! 'attachments/attachment_small', attachment: @file
+json.id @file.id
+json.title @file.title
+json.filesize number_to_human_size(@file.filesize)
+json.url download_url(@file).gsub("/api","")
+json.created_on @file.created_on
+json.is_pdf @file.is_pdf?
 json.partial! "attachment_histories/list", attachment_histories: @attachment_histories
diff --git a/lib/tasks/excellent_course_exercise.rake b/lib/tasks/excellent_course_exercise.rake
index a607c24a0..07c33d9e9 100644
--- a/lib/tasks/excellent_course_exercise.rake
+++ b/lib/tasks/excellent_course_exercise.rake
@@ -38,6 +38,8 @@ namespace :excellent_course_exercise do
         rand_num = index < pass_count - 1 ? 20 : rand(1..16)
       elsif exercise_question_ids.length == 17
         rand_num = index < pass_count - 1 ? rand(13..17) : rand(1..11)
+      elsif exercise_question_ids.length == 39
+        rand_num = index < pass_count - 1 ? rand(30..39) : rand(1..18)
       else
         rand_num = exercise_question_ids.length
       end
diff --git a/public/react/src/modules/courses/coursesDetail/CoursesLeftNav.js b/public/react/src/modules/courses/coursesDetail/CoursesLeftNav.js
index 235fd776c..16c71f942 100644
--- a/public/react/src/modules/courses/coursesDetail/CoursesLeftNav.js
+++ b/public/react/src/modules/courses/coursesDetail/CoursesLeftNav.js
@@ -721,15 +721,19 @@ class Coursesleftnav extends Component{
     let {url}=this.state;
     if (key === this.props.indexs) {
       this.props.unlocationNavfun(undefined)
+			this.props.history.replace(urls);
     } else {
       this.props.unlocationNavfun(key)
+			this.props.history.replace(urls);
     }
     if(urls!=url){
       this.props.history.replace(urls);
     }
-    if(this.props.indexs===undefined){
-			this.props.history.replace(urls);
-		}
+    // if(this.props.indexs===undefined){
+		//
+		// }else{
+		//
+		// }
   }
 
   maincontent=(item,key)=>{
diff --git a/public/react/src/modules/paths/PathDetail/DetailCards.js b/public/react/src/modules/paths/PathDetail/DetailCards.js
index e34666294..780ed4071 100644
--- a/public/react/src/modules/paths/PathDetail/DetailCards.js
+++ b/public/react/src/modules/paths/PathDetail/DetailCards.js
@@ -226,10 +226,11 @@ class DetailCards extends Component{
 					startshixunCombattype:true,
 				})
 			} else {
-				window.location.href = "/tasks/" + response.data.game_identifier;
+				// window.location.href = "/tasks/" + response.data.game_identifier;
 				// window.location.href = path
 				// let path="/tasks/"+response.data.game_identifier;
 				// this.props.history.push(path);
+				window.open("/tasks/" + response.data.game_identifier);
 			}
 		}).catch((error) => {