typos

src/ZODB/tests/testConnection.py

@@ -246,7 +246,7 @@ class UserMethodTests(unittest.TestCase):
         object will be returned. The cache doesn't keep unreferenced
         ghosts alive, although on some implementations like PyPy we
         need to run a garbage collection to be sure they go away. (The
-        next object returned my still have the same id, because Python
+        next object returned may still have the same id, because Python
         may re-use the same memory.)
 
         >>> del obj, obj2

src/ZODB/tests/testConnectionSavepoint.py

@@ -131,8 +131,9 @@ number of objects.  Make sure the cache shrinks now instead.
 
     >>> dummy = transaction.savepoint()
 
-Jython needs a GC, and needs to actually access the map to be sure the size
-is updated:
+Jython needs a GC, and needs to actually access the cache data to be
+sure the size is updated (it uses "eventually consistent" implementations for
+its weak dictionaries):
 
     >>> _ = gc.collect()
     >>> _ = getattr(cn._cache, 'data', {}).values()

src/ZODB/tests/testRecover.py

@@ -74,7 +74,7 @@ class RecoverTest(ZODB.tests.util.TestCase):
             # Note that we open the file as r+, not a+. Seeking a file
             # open in append mode is effectively a no-op *depending on
             # platform*, as the write may simply append to the file. An
-            # earlier version of this code opened the file is a+ mode,
+            # earlier version of this code opened the file in a+ mode,
             # meaning on some platforms it was only writing to the end of the
             # file, and so the test cases were always finding that bad data.
             # For compatibility with that, we do one write outside the loop

src/ZODB/tests/testSerialize.py

@@ -140,7 +140,7 @@ class SerializerFunctestCase(unittest.TestCase):
         # so force it ourselves
         environ = os.environ.copy()
         if IS_JYTHON:
-            # Jython 2.7rc2 has a bug; if it's Lib directory is
+            # Jython 2.7rc2 has a bug; if its Lib directory is
             # specifically put on the PYTHONPATH, then it doesn't add
             # it itself, which means it fails to 'import site' because
             # it can't import '_jythonlib' and the whole process fails