And you think classroom quizzes are difficult! Try answering a series of confusing word problems while breathing one-third less oxygen than you're breathing now. That's what researchers made a group of climbers do at several stops on their way to the summit of Mount Everest. Check out this interactive feature from the NOVA Everest Web site, and see how you do.
This resource can be found on the NOVA: "Everest: The Death Zone" Web site.