within / among / in / middle / center / while (doing sth) / during / (dialect) OK / all right
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.
mountain / hill / anything that resembles a mountain / CL:座[zuo4] / bundled straw in which silkworms spin cocoons / gable
山
=
丨
+
凵
:
Mnemonic symbol: 山 looks like the tip of a fork. Sherlock Holmes (sh) is climbing a mountain (山) in front of the anthill (an1). He uses a dinosaur bone (〡) as walking stick, and to have better grip he attached a fork (山) to its tip. Unfortunately he accidentally sticks the fork into a receptacle (凵) on the ground of the mountain and gets shocked.
Sherlock Holmes (sh) started a supermarket (市) in the space station's bathroom (Ø4), but all he has for sale right now are berets (亠) and towels (巾). He should have opened it at the beach!