struct student char name[10] char sex struct date birthday float Sc[14] 3 std, pers, * pstd 变量sd的结构如下: n S y m 0 23 <「struct student { char name[10]; char sex; struct date birthday; float sc[4]; } std,pers[3],*pstd; 变量std的结构如下: n s y m d 0 1 2 3