As a class experiment,
Four worms were placed in four separate test tubes:

1st in beer
2nd in wine
3rd in whiskey
4th in mineral water

The next day, the teacher shows the results:
The 1st worm in beer, dead.
The 2nd in wine, dead.
The 3rd in whiskey, dead.
The 4th in mineral water, alive and healthy.

The teacher asks the class:
“What did we learn from this experience?”

A kid down the back raises his hand and responds:
“Whoever drinks beer, wine and whiskey, doesn't have worms.”