The party last night was _____ success. We sang and danced until it came to _____ end at twelve. [ ]

A. a; an

B. a; the

C. the; an

D. 不填; an

下列程序的执行结果为______。
#include＜iostream.h＞
class Myclass

public:
void GetSum(int a);
static int Sum;
prtvate:
int A;
;
int Myclass::Sum=10;//必须在类外部对静态数据成员初始化
void Myclass::GetSum(int a)

A=a;
Sum+=A：

vold PrintSum(Myclass& A)

cout＜＜"Sum="＜＜A. Sum＜＜endl;

void main( )

Myclass M,N;
M.GetSum(3);
N.GetSum(7);
PrintSum(M);