刻苦學習

刻 = 亥 + 刂 : Mnemonic symbol: an engraver.

The boar cannot believe it when it meets Karl Marx in the elevator's bathroom! Bewildered it asks for an autograph but has nothing except for a kitchen knife and an engraver. It takes Karl Marx a quarter of an hour to engrave his message in the kitchen knife: "Dear boar, keep on fighting capitalism! Yours, Karl."

苦 = 艹 + 古 : Karl Koala decided to repent for his sins and retreated into a cloister inside the space station. There he leads a very simple life full of hardship, e.g. he gave up on eucalyptus and just eats very bitter artificial lawn.

学 = 小 + 冖 + 子 : Xu Xian wants to study scienceology and learn more about daisies. Just inside the elevator's kitchen, he put some daisies into a prize cup and covered them with a cooking top. He wants to study the growth rate of the daisies depending on the pH of the water in the prize cup.

习 = ㇆ + 亠 : Marie Curie is practising to take off her beret using a plough in the space station's entrance.

习 = ㇆ + 亠 : Marie Curie is practising to take off her beret using a plough in the space station's entrance.