坚实

坚 = 収 + 土 : Joan of Arc (ji) built a strong (坚) and sturdy (坚) burrow out of dirt (土) in front of the anthill (an1). She even equipped it with a strong (坚) radio (収) to keep contact with her troops.

实 = 头 + 宀 : Sherlock Holmes welcomes professor Skull just inside the entrance of the space station. Professor Skull has not a complete head but only a skull, and a solid understanding of solid state physics. She really is an honest person and still wears her graduation cap.