嗨，我不知道为什么我的代码没有显示出我预期的结果。练习是用C中的函数和if-else语句打印出一个2位数的拼写。当我运行代码时，它什么也没有返回。（这是初学者的练习，所以我只能想到这一点，所以很抱歉：（（）你能检查一下我错在哪里吗？非常感谢！

#include <stdio.h>

// Consider the second number in that 2-digit number when the first number is 1
void ten(char b)
{
    switch (b) {
        case(0): printf("ten"); break;
        case(1): printf("eleven"); break;
        case(2): printf("twelve"); break;
        case(3): printf("thirteen"); break;
        case(4): printf("fourteen"); break;
        case(5): printf("fifthteen"); break;
        case(6): printf("sixteen"); break;
        case(7): printf("seventeen"); break;
        case(8): printf("eighteen"); break;
        case(9): printf("nineteen"); break;
    }
}

// Consider the second number in that 2-digit number when the first number is not 1
void morethanten(char b)
{
    switch (b) {
        case(0): break;
        case(1): printf("one"); break;
        case(2): printf("two"); break;
        case(3): printf("three"); break;
        case(4): printf("four"); break;
        case(5): printf("five"); break;
        case(6): printf("six"); break;
        case(7): printf("seven"); break;
        case(8): printf("eight"); break;
        case(9): printf("nine"); break;
    }
}

int main()
{
    char a, b;
    printf("Enter your 2-digit number: ");
    scanf("%c%c", &a, &b);

    // Consider the first number in that 2-digit number
    switch (a) {
        case(0): printf("That is not a 2-digit number"); break;
        case(1): ten(b); break;
        case(2): printf("Twenty"); morethanten(b); break;
        case(3): printf("Thirty"); morethanten(b); break;
        case(4): printf("Fourty"); morethanten(b); break;
        case(5): printf("Fifthty"); morethanten(b); break;
        case(6): printf("Sixty"); morethanten(b); break;
        case(7): printf("Seventy"); morethanten(b); break;
        case(8): printf("Eighty"); morethanten(b); break;
        case(9): printf("Ninety"); morethanten(b); break;
    }
    return 0;
}

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