不止一次

不 = 丆 + 卜 : Bruno Bear (bu) is setting up a wind wheel (丆) with a voodoo staff (卜) in the space station's bathroom (Ø4). He also puts a "forbidden" sign (mnemonic symbol for 不) on it, to make clear that it may not (不) be stopped.

止 = ⺊ + 丨 + 一 : Mnemonic symbol: a barrier. James II of England (zh) is marking his area in the space station's living room (Ø3) with a big barrier (止), in front of which he sets up his pennant (⺊). He places a soldier left and right to the barrier, armed with a dinosaur bone (丨) and a flute (一) respectively.

Maud Younger (y) forgot her keys to the space station (Ø1), all she brought outside was her flute (一). She has no choice but to crash the door with the giant flute.

次 = 冫 + 欠 : Mnemonic symbol: the cube, as in words involving 三次 relate to "cubic equations" or "cube (third power)". The King of Chu (c) pulls a popsicle (冫) out of the cube (次) in the space station's bathroom (Ø4) and leaves an IOU note (欠) on the cube.