實線

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.

线 = 戋 + 纟 : Mnemonic symbol: barbed wire.

线 = 戋 + 纟 : The silk worm wants to use the floating tank in the anthill's bathroom, but there's already Marie Curie inside—and she secured the tank by setting up barbed wire all around it.