The accumulation of technological progress is by no means achieved overnight. Often behind every technological progress is the lesson of countless people, and even the price of blood.

For example, the steam engine that Zhang Yifan made has a separate condenser, adjustable valve, cylinder insulation, planetary gear, parallel motion connecting rod mechanism, centrifugal governor, pressure gauge, etc., every component can only be obtained after encountering problems and trying to improve and waste a lot of brain cells.

"Early Ming Dynasty: Saved a Princess at the Beginning" 269 This is really amazing! I am hitting it in my hand, please wait a moment,

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