What hinged surfaces on a plane's wingtips allow the aircraft to roll?

More Questions:

What do you need two of to play Double Dutch?

In what year was Boy George's autobiography published?

The Broadway hit "Rent" translates what opera to a Greenwich Village apartment?

Turnov, Rusty and Bobo appear in what stage musical?

Who wrote the novel "The Bridge Over the River Kwai"?

What was the name of King Arthur's sword?

Charleston is the capital of which US state?

A group of lions is called a what?

What disease is considered the human form of "Mad Cow's Disease"?

What bird has the largest beak relative to its body size?

Which character did Evan Handler play on the TV show "Californication"?

SpongeBob SquarePants lives in a house shaped like what?

Which 19th century French artist painted "Bathers at Asnieres"?

Who released an autobiography titled "Making Waves: The Autobiography"?

What is the capital of El Salvador?