Napa High School student Guillermo Llamas earned a chance to test his mettle in the leadership capital of the nation, Washington, D.C., earlier this month. Llamas, 17, who will be a senior next year, spent 10 days in Washington with the Congressional Youth Leadership Council, a nonprofit, nonpartisan agency that provides leadership programs to students nominated by educators around the country, and College Board, a nonprofit helping students prepare for college.