What do you call a bowling ball that falls from the sky and knocks down all the bowling pins? An Airstrike
9-11 was a round of clash of clands they knocked down 2 towers not 3
Why didn't the chicken cross the road
Cause it got knocked down on its way
What is the difference between a coconut and your ex? One is fun to knock down by throwing rocks at the other one is a coconut.
What did the man say when he knocked down the bookshelf? Looks like I've only got myshelf to blame...
I get knocked down, but I get up again, as long as I have 46 chromosomes.