What is the main idea of this paragraph? The third quality of da Vinci's character that informs our work at MIT is an enthusiastic demand for making, designing, practicing, and testing, and for solving problems in the real world. His fascination for tackling practical problems resembles the central mission of MIT: to bring "knowledge to bear on the world's great challenges" and assignment that MIT has pursued with remarkable results, from developing radar (雷达) during World War II, to developing standards for the World Wide Web today. Da Vinci taught his students to learn by doing in the same way will define your MIT education. As he wrote, "I have been impressed with the urgency of doing. Knowing is not enough; we must apply."