(of time or place) in; at; on / (indicating any indirect relation) to; toward; vis-à-vis; with regard to; for / (indicating a source) from; out of / (used in comparison) than / (used in the passive voice) by
于
=
亅
+
二
:
Mnemonic symbol: prepositions (in, at, on, to, ...) are what glue the sentence together. Honey is as sticky as glue, so I'll represent 于 by a honey jar.
Yu the Great (于) was assigned to repair the electronics of the space station's kitchen (Ø2), but instead he was snacking honey from a honey jar (于). Unfortunately his capacitor (二) got stuck in the honey and now he has to use a crowbar (亅) to lever it out.
治
=
台
+
氵
:
Due to a technical failure there is a water shortage in the space station. James II of England (zh) has taken over the task to manage (治) and regulate the water, and he does so by sitting behind a counter (台) in the space station's bathroom (Ø4) and handing out bottled water (氵).