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.
空
=
工
+
穴
:
In front of the engine, Karl Koala found some very special cave paintings. Using steel beams he constructs a protective cover. He also installs air conditioning to make the best environment possible to preserve the cave paintings.