四
=
儿
+
囗
:
Mnemonic symbol: a four-leaved clover. Socrates (s) is working out in the bathroom of the space station (Ø4). He's lifting four (四) wooden boxes (囗), and wonders why they are so heavy. He doesn't know that inside one of the four boxes, the monkey king (儿) is hiding and secretly laughing at him - until the monkey king comes out and surprises Socrates with a four-leaved clover (四).
县
=
且
+
厶
:
Marie Curie (xi) and the county manager of her home county are manufacturing maps of her home county (县) inside of the anthill's bathroom (an4). The county has a very special form which you can reproduce by smashing a fake nose (厶) with a shelf (且).
cavity of body / barrel (e.g. engine cylinder) / compartment / tune / accent of speech
腔
=
月
+
空
:
In front of the anglepod (ang1) the Queen of Hearts (qi) helps the moon (月) to install air conditioning (空) so that his cavity (腔) is always at the right temperature.