空心牆

空 = 工 + 穴 : Mnemonic symbol: an air conditioner

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.

心 = 乚 + 丶 : Marie Curie (xi) uses a shovel (乚) to dig a hole in front of the encampment ((e)n1). She wants to bury her heart (心). To the side are three petal leaves (丶), with which she wants to cover it afterwards.

墙 = 啬 + 土 : The Queen of Hearts (qi) and the stingray (啬) got married and took over the anglepod to start a new kingdom. In the kitchen (ang2) they start building their city wall (墙) out of lots of dirt (土). They also add lots of thorns to make the wall as stingy (墙) as possible.