10today.0303&position=4&par t=s1&china_variant=False> 5 EFTA_R1_021 42529 EFTA02714818 npr.org / Linton Weeks Knock. Knock.Who's there?Joe King.Joe King who?Joking like this used to be considered a sickness by some people.The knock-knock joke has been a staple o... read more <http://cdn.fli pboard.c