//生成混合题目
public string mixture(int scope)
{
string ret = "";
Random random = new Random();
for (int i = 0; i < 3; i++)
{
switch (random.Next(1, 4))
{
case 1:
ret += NumbersAndSymbols.integer(scope);
break;
case 2:
ret += NumbersAndSymbols.decimals(scope);
break;
case 3:
ret += NumbersAndSymbols.grade(scope);
break;
}
if (i != 2)
{
ret += NumbersAndSymbols.operators();
}
}
return(ret);
}
//生成四年级题目
public static string topicfour(int scope)
{
string ret;
ret = NumbersAndSymbols.integer(scope) + " " + NumbersAndSymbols.operators() + " " + NumbersAndSymbols.integer(scope) + " " + NumbersAndSymbols.operators() + " " + NumbersAndSymbols.integer(scope);
return(ret);
}