小型测试系统的设计与实现要求能够随机生成20道数学计算题（要求有加，减，乘，除），对用户结果进行判断，并能最终计算总成绩，要求用户在规定的时间内做完试题，超时自动终止并给出成绩。-Small Test System Design and Implementation of the requirements to 20 randomly generated mathematical title (requires add, subtract, multiply, divide), to the user to judge the results, and a total score of the final calculation that requires a user to a specified period of time after questions, overtime automatically terminates and gives results.