机械工程

机 = 几 + 木 : Joan of Arc (ji) made a machine (机) that fully automatically manufactures tables (几) out of Christmas trees (木) and tests it in front of the space station (Ø1).

械 = 戒 + 木 : Marie Curie (xi) finds a turning machine (机械) under a Christmas tree (木) in the elevator's bathroom (e4). Happily she proceeds to manufacture a ring (戒) for herself.

工 = 二 + 丨 : Mnemonic symbol: a steel beam, since 工 looks like the cross section of a steel beam. In front of the engine ((e)ng1), Gitta Giraffe (gu) is doing some hard work: She's stacking a capacitor (二) on a dinosaur bone (丨) on a capacitor (二). She's not very successful, but then she gets the idea to use steel beams (工) as support.

程 = 呈 + 禾 : Charlie Chaplin (ch) has been pondering over a complicated formula (程) just inside stonehenge's entrance ((e)ng2) for a long time. The formula is given on a large presentation screen (呈). While pondering over the formula Charlie Chaplin is eating a bowl of cereals (禾).

程 = 呈 + 禾 : Charlie Chaplin (ch) has been pondering over a complicated formula (程) just inside stonehenge's entrance ((e)ng2) for a long time. The formula is given on a large presentation screen (呈). While pondering over the formula Charlie Chaplin is eating a bowl of cereals (禾).