diff --git a/first_django_app.md b/first_django_app.md
index 576fb42..98cf6b7 100644
--- a/first_django_app.md
+++ b/first_django_app.md
@@ -544,7 +544,7 @@ Django provides a test **Client** (a class) to simulate a user interacting with
 
 We can try it in interactive shell following the guide
 
-#### Improving our view
+#### Test and Improve our view
 
 Add following in `tests.py`
 
@@ -665,3 +665,29 @@ Destroying test database for alias 'default'...
 
 Fix it by change `get_queryset()` method in Question. 让他它能通过将 Question 的 pub_data 属性与 timezone.now() 相比较来判断是否应该显示此 Question
 
+#### Testing the DetailView
+
+Target: hide future questions even if user type correct URL
+
+Add test cases first
+
+```python
+class QuestionDetailViewTests(TestCase):
+    def test_future_question(self):
+        """
+        The detail view of a question with a pub_date in the future returns a 404 not found.
+        """
+        future_question = create_question(question_text="Future question.", days=5)
+        url = reverse('poll:detail', args=(future_question.id, ))
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 404)
+
+    def test_past_questioin(self):
+        """
+        The detail view of a question with a pub_date in the past displays the question's text.
+        """
+        past_question = create_question(question_text='Past Question.', days=-5)
+        url = reverse('polls:detail', args=(past_question.id,))
+        response = self.client.get(url)
+        self.assertContains(response, past_question.question_text)
+```
\ No newline at end of file
diff --git a/src/polls/tests.py b/src/polls/tests.py
index 7062709..5acacfb 100644
--- a/src/polls/tests.py
+++ b/src/polls/tests.py
@@ -1,4 +1,6 @@
 import datetime
+from django.conf.urls import url
+from django.http import response
 
 from django.test import TestCase
 from django.utils import timezone
@@ -100,4 +102,23 @@ class QuestionIndexViewTests(TestCase):
         self.assertQuerysetEqual(
             response.context['latest_question_list'],
             ['<Question: Past question 2.>', '<Question: Past question 1.>']
-        )
\ No newline at end of file
+        )
+
+class QuestionDetailViewTests(TestCase):
+    def test_future_question(self):
+        """
+        The detail view of a question with a pub_date in the future returns a 404 not found.
+        """
+        future_question = create_question(question_text="Future question.", days=5)
+        url = reverse('polls:detail', args=(future_question.id, ))
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 404)
+
+    def test_past_questioin(self):
+        """
+        The detail view of a question with a pub_date in the past displays the question's text.
+        """
+        past_question = create_question(question_text='Past Question.', days=-5)
+        url = reverse('polls:detail', args=(past_question.id,))
+        response = self.client.get(url)
+        self.assertContains(response, past_question.question_text)
\ No newline at end of file
diff --git a/src/polls/views.py b/src/polls/views.py
index 7d6e42c..692a93d 100644
--- a/src/polls/views.py
+++ b/src/polls/views.py
@@ -24,6 +24,12 @@ class DetailView(generic.DetailView):
     model = Question
     template_name = 'polls/detail.html'
 
+    def get_queryset(self):
+        """
+        Excludes any questions that aren't published yet
+        """
+        return Question.objects.filter(pub_date__lte=timezone.now())
+
 class ResultsView(generic.DetailView):
     model = Question
     template_name = 'polls/results.html'