中西合併

中 = 丨 + 口 : Mnemonic symbol: a dart board, because you always try to hit the center.

Julian Giant Squid (zhu-) is throwing dinosaur bones (丨) as darts on a dart board in front of the engine ((e)ng1). To make it a bit more difficult he's throwing mandarins (口) into the air as well and skewers them up right in the center (中 is a mandarin skewered on a dinosaur bone) in mid flight with the dinosaur bones. He's still able to consistently hit the center (中) of the dart board.

西 = 兀 + 囗 : The wild west is largely recognized by the symbol of the cowboy hat.

西 = 兀 + 囗 : Marie Curie has gone crazy from the loneliness in space. In front of the space station, she sits inside of a large wooden box, wearing a cowboy hat and playing a 胡兀尔 fiddle, thinking that she's participating in a square dance in the wild west.

合 = 亼 + 口 : Mnemonic symbol: a tube of glue.

In the elevator's kitchen (e2), Hamlet (h) is preparing holiday decorations. He wants to be lazy and cover Halloween as well as Christmas at the same time, so he carved out a mandarin (口) and glued a pointed cap (亼) to its top using a tube of glue (合).

并 = 丷 + 开 : Brunhilde and a mean crocodile are amalgamating to a new super form in the engine's bathroom. They are forming the connection with bottle openers.