The research is so designed that once ____ nothing can be done to change it.

What do you think of tomorrow’s football match— ____ difficult for us _______ the match

I do not mind her criticizing me, but _____ is how she does it that I object to.

There are only ________ new words in the book, but I know _______ of them.

Never believe all ____ you hear, never regret what you have never lost, and never throw away what you have in your hands.