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.
中
=
丨
+
口
:
Mnemonic symbol: a dart board, because you always try to hit the center.
Julian Giant Squid (zhu-) is throwing dinosaur bones (丨) as darts on a dart board in front of the engine ((e)ng1). To make it a bit more difficult he's throwing mandarins (口) into the air as well and skewers them up right in the center (中 is a mandarin skewered on a dinosaur bone) in mid flight with the dinosaur bones. He's still able to consistently hit the center (中) of the dart board.