Back porting changeset db302b88fdb6 to 3.4 branch, which fixed multiple documentation typos.

Related Issues:

#issue21528
#issue24453
diff --git a/Doc/library/select.rst b/Doc/library/select.rst
index 734e426..5334af8 100644
--- a/Doc/library/select.rst
+++ b/Doc/library/select.rst
@@ -207,7 +207,7 @@
    .. warning::
 
       Registering a file descriptor that's already registered is not an
-      error, but the result is undefined. The appropiate action is to
+      error, but the result is undefined. The appropriate action is to
       unregister or modify it first. This is an important difference
       compared with :c:func:`poll`.