1. [单选题]有以下程序: #includeiostream> #includemath> using namespace std; class point { private: double x; double y; public: point(double a,double B) { x=a; y=b; } friend double distance (point a,point B) ;
A. 5
B. 4
C. 6
2. [单选题]SQL用于显示部分查询结果的TOP短语,必须与下列哪个短语同时使用才有效( )。
A. HAVING
B. DISTINCT
C. ORDERBY
D. GROUPBY