n Thanks to flight attendant Kathleen Keutmann of Henderson, Nev., who gave us the answer as to what “cross-check” means, as often heard in cockpit announcements. It’s the checking of your neighboring flight attendant’s door, as an extra precaution to ensure that the doors are properly armed at departure and disarmed at arrival. Kathleen says this helps to prevent sliding-ramp emergency exits from opening inadvertently.

As mentioned in a previous column, George Lucas got the first name of his Indiana Jones character from his pet Alaskan malamute. Director Steven Spielberg didn’t like Lucas’ first choice for the character’s last name, which was originally:

A) Wayne

B) Armstrong

C) McFly

D) Smith

Friday’s answer: The world’s busiest artificial waterway is Germany’s Kiel Canal, which links the North and Baltic Seas. In 2007, it handled an average of 118 ships per day.