考古學

考 = ⺹ + 丂 : Karl Marx (k) has to take an exam (考) in the artoa's living room (ao3). It is very difficult for him because he has to wear a breathing mask (丂) due to the open fire, and he also has to wear a huge crown (⺹) which makes it difficult for him to see the exam papers.

古 = 十 + 口 : Mnemonic symbol: at least on German maps, this character actually resembles a cloister.

Oh no! Gitta Giraffe (gu) found that the golden cross (十) broke off of the cloister (古) in the space station's living room (Ø3)! She skewers a mandarin (口) on top of the cloister so that she can skewer the broken off cross back on to fix it.

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.