What does error code 18 indicate? The device is not configured properly.
The device is unable to start.
You need to reinstall the drivers for the device.
The device is disabled.

4. what is the reason for including the following code snippet in the header file animal.h? #ifndef animal_h #define animal_h class animal { public: animal(); animal(double new_area_hunt); void birth(); void hunt(double new_area_hunt); void death(); double get_area_hunt() const; private: double area_hunt; }; #endif