一个随机变量如果是       、       、       偶然因素作用之和，它就服从或近似服从正态分布.

有以下程序 struct S{int n；int a[20]；}；voidf(struct S* p){int,i,j,t；for(i=0；in一1；i++)for(j=i+1；jn；j++)if(p->a [i]>p->a[j]){t=p->a[i]；p->a[i]=p->a[j]；P->a[j]=t；}} maln(){int i；struct S s={10,{2,3,l,6,8,7,5,4,10,9}}；f(&s)；for(i=0；i

A．1,2,3,4,5,6,7,8,9,10,

B．10,9,8,7,6,5,4,3,2,1,

C．2,3,1,6,8,7,5,4,10,9,

D．10,9,8,7,6,1,2,3,4,5,