儿
=
丿
+
乚
:
Mnemonic symbol: "son" (儿) sounds similar to "Sun" like in "Sun Wu Kong", so it's gonna be represented by the monkey king. Albert Einstein (Ø-) and Sun Wu Kong (儿) are fighting in the space station's kitchen (-Ø2). Their weapons: Albert Einstein has a shovel (乚), and Sun Wu Kong has a banana (丿).
井
=
二
+
丿
+
丨
:
Joan of Arc is digging a well inside engine. At first she was doing it by hand, but then she hooked up a capacitor to a banana and a dinosaur bone, which dig for her using the electrical energy.