What do you get if you cross a joke with a rhetorical question?
You get a pun!

A pun is a play on words, often involving a homophone or a near-homophone. In this case, the pun is on the word cross. A cross can be a religious symbol, but it can also mean to mix or combine two things. So, when you cross a joke with a rhetorical question, you get a pun.

Here is another example of a pun:

> What do you call a fish with no eyes? Fsh!

The word fsh is a pun on the word fish. The f sound is pronounced the same as the ph sound in fish, but without the h. So, the joke is that a fish with no eyes would be pronounced fsh.

Puns can be funny because they play on the ambiguity of language. They can also be clever and creative. If you're looking for a way to make people laugh, try using a pun.
I don't get why this is a pun (cross thing) can you explain again?