单项选择题
A.引用传递B.被调函数直接访问主调函数中的局部变量C.指针传递D.值传递
A.void fun（char x，double y ）B.char fun（char c，double d ）C.char function（char a，double b ）D.char fun（double x，char y ）
A.void Area（double r）{double s；s =3.14*r*r；return s；}B.double Area（）{double s；s =3.14*r*r；return s；}C.double Area（double r）{double s；s =3.14*r*r；return s；}D.double Area（double r）{Area =3.14*r*r；}