The nongno — a pulley on the end of a long pole — 230 years on

Why doesn't a tower crane fall over?

An apartment site · arm length 60 m

A model of an apartment building site on a grey table. The long arm of a yellow tower crane reaches to the right

The story behind this board

It reads far more easily after you have tried it.

The Geojunggi and Suwon Hwaseong — the machines that finished a ten-year job in under three Moment Lever Pulley Previous board — load the stone onto the cart
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