二十一条

二 = 一 : Mnemonic symbol: a capacitor, because the two strokes remind me of the symbol in electrical drawings. Albert Einstein (Ø) is experimenting with a capacitor (二) in the space station's bathroom (Ø4). He finds that it's uncomfortable to discharge a capacitor using two flutes (一).

十 = 一 + 丨 : Mnemonic symbol: a holy cross. Sherlock Holmes (sh-) is investigating a very strange thing he found in the kitchen of the space station (-2): A big pyramid made of ten (十) crosses (十), which are in turn made out of flutes (一) and dinosaur bones (丨).

Maud Younger (y) forgot her keys to the space station (Ø1), all she brought outside was her flute (一). She has no choice but to crash the door with the giant flute.

条 = 夂 + 朩 : Mnemonic symbol: a bungee cord.

条 = 夂 + 朩 : Mother Teresa helps to clear a sewage pipe just inside the aorta's kitchen. With a bungee cord, she fishes a heap of high heels out of the sewage pipe.