Here -------a Double Ninth cake and some flowers for you.A.am b.is c are

Here -------a Double Ninth cake and some flowers for you.A.am b.is c are There are （） as many people here today.(a) double (b) twice(c) second(d) two #includeusing namespace std;#define PI 314159double area(double radius=0);double area(double a,double b);double area(double a,double b,double h);double area(double a,double b,double c,int);int main(){cout 有句C语言看不懂double f (double a, double b, double c,double d, double x) double *p,a; *p operator=是什么意思啊# include double sum(double a,double b);double subtract(double a,double b);double divide(double a,double b);double multiply(double a,double b);main(){int choice;char operator;double a,b;double (*func)();printf( * * * * * double double double double double double double double Double double double double