diff --git a/app/models/item_bank.rb b/app/models/item_bank.rb
index 840f488d8..242b7de92 100644
--- a/app/models/item_bank.rb
+++ b/app/models/item_bank.rb
@@ -19,38 +19,26 @@ class ItemBank < ApplicationRecord
   end
 
   def apply?
-    !public && ApplyAction.where(container_type: "ItemBank", container_id: id, status: 0).exists?
+    !public && ApplyAction.exists?(container_type: "ItemBank", container_id: id, status: 0)
   end
 
   def type_string
-    result = case item_type
-             when "SINGLE"
-               "单选题"
-             when "MULTIPLE"
-               "多选题"
-             when "JUDGMENT"
-               "判断题"
-             when "COMPLETION"
-               "填空题"
-             when "SUBJECTIVE"
-               "简答题"
-             when "PRACTICAL"
-               "实训题"
-             when "PROGRAM"
-               "编程题"
-             end
-    result
+    case item_type
+    when "SINGLE"     then "单选题"
+    when "MULTIPLE"   then "多选题"
+    when "JUDGMENT"   then "判断题"
+    when "COMPLETION" then "填空题"
+    when "SUBJECTIVE" then "简答题"
+    when "PRACTICAL"  then "实训题"
+    when "PROGRAM"    then "编程题"
+    end
   end
 
   def difficulty_string
-    result = case difficulty
-             when 1
-               "简单"
-             when 2
-               "适中"
-             when 3
-               "困难"
-             end
-    result
+    case difficulty
+    when 1 then "简单"
+    when 2 then "适中"
+    when 3 then "困难"
+    end
   end
 end