diff --git a/Code/Day 1_Data_Preprocessing.ipynb b/Code/Day 1_Data_Preprocessing.ipynb
index 9f26c9c..7d250ac 100644
--- a/Code/Day 1_Data_Preprocessing.ipynb	
+++ b/Code/Day 1_Data_Preprocessing.ipynb	
@@ -41,23 +41,10 @@
    "metadata": {},
    "outputs": [
     {
-     "name": "stdout",
      "output_type": "stream",
+     "name": "stdout",
      "text": [
-      "Step 2: Importing dataset\n",
-      "X\n",
-      "[['France' 44.0 72000.0]\n",
-      " ['Spain' 27.0 48000.0]\n",
-      " ['Germany' 30.0 54000.0]\n",
-      " ['Spain' 38.0 61000.0]\n",
-      " ['Germany' 40.0 nan]\n",
-      " ['France' 35.0 58000.0]\n",
-      " ['Spain' nan 52000.0]\n",
-      " ['France' 48.0 79000.0]\n",
-      " ['Germany' 50.0 83000.0]\n",
-      " ['France' 37.0 67000.0]]\n",
-      "Y\n",
-      "['No' 'Yes' 'No' 'No' 'Yes' 'Yes' 'No' 'Yes' 'No' 'Yes']\n"
+      "Step 2: Importing dataset\nX\n[['France' 44.0 72000.0]\n ['Spain' 27.0 48000.0]\n ['Germany' 30.0 54000.0]\n ['Spain' 38.0 61000.0]\n ['Germany' 40.0 nan]\n ['France' 35.0 58000.0]\n ['Spain' nan 52000.0]\n ['France' 48.0 79000.0]\n ['Germany' 50.0 83000.0]\n ['France' 37.0 67000.0]]\nY\n['No' 'Yes' 'No' 'No' 'Yes' 'Yes' 'No' 'Yes' 'No' 'Yes']\n"
      ]
     }
    ],
@@ -109,12 +96,12 @@
     }
    ],
    "source": [
-    "# If you use the newest version of sklearn, use the lines of code commented out",
-    "# from sklearn.impute import SimpleImputer",
-    "# imputer = SimpleImputer(missing_values=\"NaN\", strategy=\"mean\")",
-    "from sklearn.preprocessing import Imputer\n",
+    "# If you use the newest version of sklearn, use the lines of code commented out\n",
+    "from sklearn.impute import SimpleImputer\n",
+    "imputer = SimpleImputer(missing_values=np.nan, strategy=\"mean\")\n",
+    "#from sklearn.preprocessing import Imputer\n",
     "# axis=0表示按列进行\n",
-    "imputer = Imputer(missing_values = \"NaN\", strategy = \"mean\", axis = 0)\n",
+    "#imputer = Imputer(missing_values = \"NaN\", strategy = \"mean\", axis = 0)\n",
     "imputer = imputer.fit(X[ : , 1:3])\n",
     "X[ : , 1:3] = imputer.transform(X[ : , 1:3])\n",
     "print(\"---------------------\")\n",
@@ -329,9 +316,9 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.6.5"
+   "version": "3.8.3-final"
   }
  },
  "nbformat": 4,
  "nbformat_minor": 2
-}
+}
\ No newline at end of file