自动可乐售货机 用两个发光二极管分别模拟售出面值为5角和1元的可乐，购买者可通过开关选择一种面值的可乐，灯亮时表示可乐售出。用开关分别模拟1元，5角人民币投入，用发光二极管分别代表着回剩余的硬币。 -Auto-Cola vending machine were simulated with two light-emitting diode sold in denominations of 50 cents and $ 1 Coke, buyers can switch to choose a