Winter is my favorite. It’s a beautiful season, ______ when it snows.
--- Is this your sister’s key, John?--- No, it isn’t. ______ is in the bag.
—Have you ever seen ______ film The Flowers of War 2011?—I think it is ______ interesting one.
“Do you mind if I sit here?” “_____ .It’s for Mr. Brown.”
Mr. Wu is a teacher with _______. He often tells us some of his unusual _______ in America.
There are in the reading room, but many of those books aren’t to read.