—Why do you get up so early in the morning,Tracy?

—I generally make it a _________to be up by 7 to read English.[ ]

A. plan                          

B. wish

C. secret                      

D.  rule

阅读以下说明和C++代码，填充代码中的空缺。
[说明]
下面的程序用来计算并寻找平面坐标系中给定点中最近的点对(若存在多对，则输出其中的一对即可)。程序运行时，先输入点的个数和一组互异的点的坐标，通过计算每对点之间的距离，从而确定出距离最近的点对。例如，在图所示的8个点中，点(1,1)与(2,0.5)是间距最近的点对。

[C++代码]
#include ＜iostream＞
#inc lude ＜cmath＞
using namespace std;
class GPoint
private:
double x,y;
public:
void setX(double x)this-＞x=x;
void setY(double Y)this-＞y=Y;
double getX()return this-＞x;
double getY()return this-＞y;
;
class ComputeDistance
public:
double distance(GPoint a,GPoint b)
return sqrt((a.getX()-b.getX())*(a.getX()-b.getx())+(a.getY()-b.getY())*(a.getY()-b.getY()));

;
int main()

int i,j, numberofP0ints=0;
cout＜＜"输入点的个数:";
cin＞＞numberOfPOints;
______ points=new GPoint[numberOfPoints];//创建保存点坐标的数组
memset(points,0,sizeof(points));
cout＜＜"输入"＜＜numberOfPoints＜＜"个点的坐标:";
for(i=0;i＜numberOfPoints；i++)
double tmpx,tmpy;
Cin＞＞tmpx＞＞tmpy;
points[i].setX(tmpx);
points[i].setY(tmpy);

______ computeDistance=new ComputeDistance();
int p1=0,p2=1;//p1和p2用于表示距离最近的点对在数组中的下标
double shortestDistance=computeDistance-＞distance(points[p1],points[p2]);
//计算每一对点之间的距离
for(i=0;i＜numberOfPoints;i++)
for(j=i+1;j＜______;j++)
double tmpDistance=computeDistance-＞______;
if(______)
p1=i;p2=j;
shortestDiStance=tmpDistance;



cout＜＜"距离最近的点对是:(";
cout"points[p1].getX()＜＜", ”＜＜points[p1].getY()＜＜")和(";
cout＜＜points[p2].getX()＜＜","＜＜points[p2].getY()＜＜")"＜＜endl;
delete computeDiStance;
return 0;