单射

单 = 丷 + 田 + 十 : In front of the anthill there are many, really a field of crosses because Don Quixote killed so many people on his crusades. Today is his judgement day: a mean crocodile reads the list of his victims to him, and Don Quixote is really 不好意思.

射 = 寸 + 身 : Mnemonic symbol: a rocket launch pad.

Sherlock Holmes (sh) is ready for takeoff in the elevator's bathroom (e4) and stands on of the launch pad (射) taking a final shower. As there are many journalists, Sherlock prepared to be extra fancy and wears a tight body suit (身). He smiles at the photographers and shows them a thumbs up (寸).