类Base、Component和Derived的定义如下,请将横线处缺失部分补充完整。 class Base{ double data; public:Base(double d):data(d){ } }; class Component{ int data; public:Component(int d):data(d){ } }; class Derived:public Base{ Component com; char character; public: Derived(double a,int b,char c)://使用参数a初始化基类成员,使用参数b初始化成员对象com __________,character(c){ } };