小甲鱼笔记#一个关于指针所占空间的问题

#include <stdio.h>

int main()
{
    char a = 'F';
    int b =123;
    
    char *pa = &a;
    int *pb = &b;
    
    printf("a = %c\n", *pa);
    printf("b = %d\n", *pb);
    
    *pa = 'C';
    *pb += 1;
    
    printf("now, a = %c\n", *pa);
    printf("now, b = %d\n", *pb);
    
    printf("The addr of a is %p\n", pa);
    printf("The addr of b is %p\n", pb);
    
    printf("The length of pa is %d\n", sizeof(pa));
    printf("The length of pb is %d\n", sizeof(pb));
    
    return 0;
}

输出为：

a = F
b = 123
now, a = C
now, b = 124
The addr of a is 0060FF07
The addr of b is 0060FF00
The length of pa is 4
The length of pb is 4

既然指针所占内存空间为4个字节，为什么地址相差8个字节呢？