小学数学测试程序，随即逐个生成20题计算题，没当用户大国一题后出现第二道题目，

小弟才疏学浅，各位大哥大姐见谅哈-Primary Mathematics test program, then generate the 20 questions one by one calculation problems, no problems when the user powers after a second subject, brother Caishuxueqian, Ladies and Big Brother Big Sister forgive me Ha! ! !