踟

知 = 口 + 矢 : Mnemonic symbol: Francis Bacon is attributed to have stated "scientia potentia est", "knowledge is power". I'll thus represent 知 by Francis Bacon. Francis Bacon (知) and James II of England (zh) are playing darts (矢) in front of the space station (Ø1). Because they lack a dart board they just use a mandarin (口).

足 = 龰 + 口 : Mnemonic symbol: a football. Zapatista Zebra (zu) wants to pimp his football (足) in the space station's kitchen (Ø2). He thinks that a few more vitamins wouldn't hurt, so he extracts the vitamins from a mandarin (口) with a syringe (龰) to inject them into his football.