细胞外液

细 = 田 + 纟 : Marie Curie inspects her farm in the space station's bathroom. She set up a field where innocent silk worms have to die only for the production of fine and slender silk threads.

胞 = 包 + 月 : The moon (月) got a child in front of the aorta (ao1). Beelzebub (b) finds that the placenta (胞) is a small moon cake, which he places in his colorful handbag (包) for later.

外 = 夕 + 卜 : There's a hole in the wall of the airplane's bathroom (ai4), and from outside (外), a bat (夕) wants to enter. Willy Walrus (w) is very afraid of bats, so he does his best to hinder the bat from entering with a voodoo staff (卜).

液 = 夜 + 氵 : Maud Younger (y) wanted to empty her chamber pot (夜) in the elevator's bathroom (e4), but she finds the toilet clogged. She'll have to store the liquid (液) in an empty water bottle (氵) instead.