C 错误：预期的声明说明符或“*”标记之前的“...”

所以我正在学习数据结构，并且对 C 非常陌生。我正在尝试制作一个接受学生 ID 和课程编号的函数，输出将是学生姓名和课程名称。我目前被困在输入部分。这是我到目前为止的代码：

typedef struct Student Student;
typedef struct Course Course;
typedef struct Node Node;
typedef struct Node* NodePtr;

struct Student{
    int id;
    char name[30];
    double gpa;
    int ch;
};

struct Course{
    int id;
    char code[10];
    char name[30];
    int ch;
};

void displayStudents() {

     struct Student students[10]={
        {1, "ahmed" ,3.6,43},
        {2, "mohamed", 3.2, 40},
        {3,"hassan", 3.0, 41},
        {4, "hossam", 2.5, 35},
        {5, "hany", 2.3, 32},
        {6, "hala", 2.7, 37},
        {7, "hana", 2.8, 33},
        {8, "ramadan",3.8,46},
        {9, "sameh",3.7,43},
        {10, "nour",3.3,42}
     };

      for(int i=0; i<10; i++) {
        printf("%d,%s,%lf, %d", students[i].id, students[i].name, students[i].gpa, students[i].ch);
        printf("\n");
      }

}

void displayCourses() {

    struct Course courses[3] = {
    {30, "CS212", "DataStructure", 3},
    {40, "CS233", "Architecture", 3},
    {50, "GM300", "Multimedia", 3}

    };

    for (int i=0; i<3; i++) {

        printf("%d - %s - %s - %d", courses[i].id, courses[i].code, courses[i].name, courses[i].ch);
        printf("\n");
    }


}

void Registeration(struct Student student, *struct Course courses) {

          printf("Select a student: \n");
          gets(student.name);
          printf("Enter his ID: ");
          scanf("%d", &student.id);
          printf("Select a course: ");
          scanf("%d",&course.id);


}

我在注册功能中遇到错误。我尝试删除指针但它引起了其他问题，我也尝试了很多其他东西但无济于事。

这是错误：

||=== Build: Debug in Data Structure Project (compiler: GNU GCC Compiler) ===|
C:\Users\Shiko\Desktop\C Tutorials\Data structure project\main.c|155|error: expected declaration specifiers or '...' before '*' token|
||=== Build failed: 1 error(s), 0 warning(s) (0 minute(s), 0 second(s)) ===|