机
=
几
+
木
:
Joan of Arc (ji) made a machine (机) that fully automatically manufactures tables (几) out of Christmas trees (木) and tests it in front of the space station (Ø1).
械
=
戒
+
木
:
Marie Curie (xi) finds a turning machine (机械) under a Christmas tree (木) in the elevator's bathroom (e4). Happily she proceeds to manufacture a ring (戒) for herself.
码
=
石
+
马
:
Just when Mahatma Gandhi (m) and the unicorn (马) entered the ashram (a3) a giant rock (石) fell down and trapped them inside. There is an inscription written on it: if they ever want to leave, they will have to find the secret number (码) and say it out loud. There is also a hint: "how many roads must a man walk down?"