木工

木 = 八 + 十 : Mnemonic symbol: a Christmas tree.

Malte Monkey (mu) is setting up a Christmas tree (木) in the bathroom of the space station (Ø4). He decorates the tree with eight-balls (八) and puts a holy cross (十) at the top of the tree.

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.