单选题 考虑下面代码,说法正确的是: //apple.h class Apple { public: Apple(int e):power(e) { } int getEnergy( ) const { return power; } void eatenBy(Mouse * m) { int w = m->getWeight( ); m->setWeight(w+power*0.5); } private: int power; }; //mouse.h class Mouse { public: Mouse(int w):weight(w) { } int getWeight( ) const { return weight; } void setWeight(int w) { weigth =w; } void eat(Apple * one) { one->eatenBy(this); } private: int weight; }