複線

复 = 𠂉 + 日 + 夂 : Mnemonic symbol: a photocopier.

Frieda Fox (fu) and the sun (日) have to wear high heels (夂) in the space station's bathroom (Ø4). The high heels are locked, and they only have one key (𠂉). They know that the key is very fragile and can only be used once, so they use a photocopier (复) to create more keys so that both of them can be freed.

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.