领空

领 = 令 + 页 : Li Qingzhao wants to explore the catacombs below engine, which can only be accessed from inside engine. Because it is so dangerous down there she has to hand in a piece of paper with her name and gets back a name-tag which she has to clip to her dog collar so that she can be identified should something go wrong.

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.