数字游戏第二季剧情介绍：  Do you have courage? Confidence? Commitment to a goal? If you do, you might be tougher than you think. Toughne…

数字游戏第二季剧情介绍：  Do you have courage? Confidence? Commitment to a goal? If you do, you might be tougher than you think. Toughness is about more than just strength; explore the science behind the basic building blocks of toughness, and learn how to boost your natural fortitude to become tough as nails.