Question: Two men went into a restaurant. They sat at a table and the waiter came by and asked, "What do you want to drink?"
The first man said, "I'll have H20."
The second man said, "I'll have H20 too."
The second man died.
Answer: The second man said "I'll have H20 too." This sounds just like "H202" and H202 is a hydrogen paroxide which is deadly when drank.