万国邮联

万 = 丆 + ㇆ : As mnemonic symbol I choose a neuron, since each neuron is said to connect to 10000 others.

万 = 丆 + ㇆ : Willy Walrus needs to dig up the floor in the anthill's bathroom, but he is tired of doing so manually with a plough. To make his life easier, he sets up a wind wheel for electricity, connects a neuron to the wind wheel and the plough to transmit the electricity and uses his new DIY electric plough to dig much faster.

国 = 囗 + 玉 : Mnemonic symbol: a nation's flag. Let's say the Chinese flag.

In the observatory's kitchen (o2) Gitta Giraffe (gu) is practising her ballet performance. She got a whole crate (囗) full of jade bracelets (玉) and flags (国) and fixed one flag to each jade bracelet. This makes a perfect combination for throwing the ring with the flag waving behind it and catching the ring again after a few pirouettes.

邮 = 由 + 阝 : Maud Younger (y) received a postcard (邮) in the outhouse's kitchen (ou2). The postcard is from the imperator (阝) and shows himself enjoying a cuba libre (由). On the postcard he invites Maud to visit him in his holiday lodge.

联 = 关 + 耳 : Li Qingzhao (li) invented a machine able to combine (联) her hair into braids, and she is trying it out for the first time in the anthill's kitchen (an2). Just as the machine starts Li Qingzhao realizes it is going to combine both of her ears (耳) into one braid she quickly hits the machine's off button (关).