We're all familiar with the high-pitched squeak of basketball shoes on the court during games, or tires squealing on pavement. Scientists conducted several experiments and discovered that the geometry of the sneakers' tread patterns determines the squeak's frequency, enabling the team to make rubber blocks set to specific frequencies and slide them across glass surfaces to play Star Wars' "Imperial March."
Thus, we can try making our first primitive command line that simply echoes whatever the user typed:
。体育直播对此有专业解读
30대女 차 손잡이에 ‘소변·침 테러’…범인은 옆집 40대 아저씨
代码重构：它没有直接甩代码，而是先思考了“设计模式”的选择（工厂模式 vs 策略模式），最终选择了适合扩展的策略模式。