一是一，二是二

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.

是 = 旦 + 龰 : Mnemonic symbol: a skull, from "to be or not to be".

Sherlock Holmes (sh) starts his day in the space station's bathroom (Ø4) with a mug of coffee (旦). Holding a skull (mnemonic symbol for 是) in his hands, he asks himself "to be, or not to be" (是). He wonders if he can make the skull come back to life using lots of coffee, and injects coffee from his mug into the skull using a syringe (龰).

是 = 日 + 下 + 人 : Mnemonic symbol: a skull, from "to be or not to be".

Sherlock Holmes (sh) watches the Neanderthal Man (人) trying to climb to the sun (日) on a ladder (下) in the space station's bathroom (Ø4). Sherlock is afraid that he'll open the window, so he puts on a big skull (是) and scares him off.

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).