I went to the library and asked the librarian if they had any books on Pavlov's dogs and Schrödinger's cat.

She said it rang a bell, but she wasn't sure if it was here or not.

I tried to make a joke about bread, but I kneaded to work on it.

Why did the can crusher quit his job?

Because it was soda pressing!

Why did the bicycle fall over?

Because it was two-tired!