From card no. V02FXX1:

A man walks into a bar and says, "I'd like an H-2-oh." another man says, "I'll have an H-2-oh-2." The second man dies.
A man walks into a bar and says, "I'd like an H-2-oh." another man says, "I'll have an H-2-oh-2." The second man dies I approve of this sco i i ience joke. *