21.  The worst thing you can do is underestimate an opponent.

22.  This is positively the worst thing that I can even imagine.

23.  It was the worst thing that could have happened.

24.  The worst thing that can happen --

25.  What is the worst thing that can happen when organising a tour?

26.  I tried to think of the worst thing that Quigley had done.

27.  And do you know what is the worst thing about all of this?

28.  WHEN THE worst thing has happened that can happen, a certain kind of relief sets in.

29.  But this is the worst possible thing that could have happened.

30.  It is just the worst possible thing to have happened.