Fixed wording from drop two columsn to drop three columns

2-Working-With-Data/07-python/notebook-covidspread.ipynb

@@ -1608,7 +1608,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "> **Note** how we use `[3:]` to remove first two elements of a sequence that contain geolocation of a country. We can also drop those two columns altogether:"
+    "> **Note** how we use `[3:]` to remove first three elements of a sequence that contain geolocation of a country. We can also drop those three columns altogether:"
    ]
   },
   {