What do the following sentences have in common?

1. Peanuts can cause some people to break out in a rash.
2. The flashing sign said to slow down up ahead.
3. He always goes off on a tangent.
4. I graduated before after-hour drinking became a problem.
5. Your time is over under the rules of this debate.

Answers:

Each sentence contains two opposite prepositions side by side:

1. break OUT IN a rash
2. slow DOWN UP ahead
3. goes OFF ON a tangent
4. graduated BEFORE AFTER-hour
5. time is OVER UNDER the rules

Credit:
NY Times Crossword
February 17, 2005
Patrick Merrell (#1-3)