diff --git a/module3/exo1/analyse-syndrome-grippal.ipynb b/module3/exo1/analyse-syndrome-grippal.ipynb
index a4d53db7564cf8293ac400f927fe294ed27073f6..2bc78cf1abb64f29e6f98d4a48c39320b5302887 100644
--- a/module3/exo1/analyse-syndrome-grippal.ipynb
+++ b/module3/exo1/analyse-syndrome-grippal.ipynb
@@ -2185,10 +2185,12 @@
     }
    ],
    "source": [
+    "# verifier si la différence temporelle est supérieure à 1 seconde\n",
     "periods = sorted_data.index\n",
     "for p1, p2 in zip(periods[:-1], periods[1:]):\n",
     "    delta = p2.to_timestamp() - p1.end_time\n",
     "    if delta > pd.Timedelta('1s'):\n",
+    "# afficher les paires de périodes consécutives qui ont une difference temporelle\n",
     "        print(p1, p2)"
    ]
   },
@@ -2201,7 +2203,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 10,
+   "execution_count": 9,
    "metadata": {},
    "outputs": [
     {
@@ -2226,16 +2228,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 11,
+   "execution_count": 10,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "<matplotlib.axes._subplots.AxesSubplot at 0x7fdceab16860>"
+       "<matplotlib.axes._subplots.AxesSubplot at 0x7fc9e29c0588>"
       ]
      },
-     "execution_count": 11,
+     "execution_count": 10,
      "metadata": {},
      "output_type": "execute_result"
     },
@@ -2286,7 +2288,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 12,
+   "execution_count": 11,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2306,7 +2308,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
+   "execution_count": 12,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2330,16 +2332,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 14,
+   "execution_count": 13,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "<matplotlib.axes._subplots.AxesSubplot at 0x7fdce897a208>"
+       "<matplotlib.axes._subplots.AxesSubplot at 0x7fca186830f0>"
       ]
      },
-     "execution_count": 14,
+     "execution_count": 13,
      "metadata": {},
      "output_type": "execute_result"
     },
@@ -2434,16 +2436,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 16,
+   "execution_count": 14,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "<matplotlib.axes._subplots.AxesSubplot at 0x7fdce8948dd8>"
+       "<matplotlib.axes._subplots.AxesSubplot at 0x7fc9e0880940>"
       ]
      },
-     "execution_count": 16,
+     "execution_count": 14,
      "metadata": {},
      "output_type": "execute_result"
     },