不知輕重

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.

知 = 口 + 矢 : Mnemonic symbol: Francis Bacon is attributed to have stated "scientia potentia est", "knowledge is power". I'll thus represent 知 by Francis Bacon. Francis Bacon (知) and James II of England (zh) are playing darts (矢) in front of the space station (Ø1). Because they lack a dart board they just use a mandarin (口).

轻 = 车 + 又 + 工 : The Queen of Hearts has been training a lot recently and poses before her next boxing battle. She's driving around in her cabriolet bending steel beams wearing her boxing gloves easily, swinging the beams as if they were as light as feathers.

重 = 千 + 里 : Chantal Chicken set a new world record in the engine's kitchen. She repeatedly rode a space elevator up and down, one thousand times in total. For setting the world record she got a sunflower.

重 = 千 + 里 : This one looks like a space elevator. The two top strokes are the heavens, the two bottom strokes are the earth and the part in between is the space elevator.

重 = 千 + 里 : Julian Giant Squid installed a space elevator in the engine's bathroom, and now he wants to find out how heavy the load can be. For his first trip he loads 1000 times 1 kilo, and to celebrate the grand opening, he brought a sunflower.