1. By the time the competitors in the Eco-Challenge finish the difficult 150+ mile course over 8 days, they will have rafted down a river, hiked through jungle, climbed a volcano, and kayaked through shark-infested waters. 2. By the time Anne graduates with her bachelor's degree next June, she will have attended 4 colleges over more than 7 years of study, and plans to continue on for a Ph.D., meaning she will be a student for over 13 years total. 3. By the time everyone arrives for dinner this afternoon, Sarah will have been cooking in the kitchen for over 7 hours and hopefully will have finished everything by then. 4. By