吴
=
口
+
天
:
Mnemonic symbol: the water buffalo from Wu.
Willy Walrus (w) enters the space station (Ø2) with a big mandarin (口) in his hands. The water buffalo (吴) sees it and begins to pant heavily, slightly in panic. Fortunately there is an angel (天) around to calm him down and let him know that it's not the sun he's fearing.
镇
=
真
+
钅
:
James II of England (zh) had the replicator (真) create too much food and now he forces (镇) it down the encampment's toilet ((e)n4) using a golden harpoon (钅).
宇
=
于
+
宀
:
Yu the Great (yu) just earned her PhD in the space station (Ø3) and is proudly putting on her graduation cap (宀). She was measuring cosmic (宇) rays by investigating the traces they left in a honey jar (于) and is demonstrating her experiment for the camera.