Technological power starts with upgrading lenses

Kang Chi was originally just a maintenance worker, but suddenly got the "item upgrade system".
As long as you make it yourself, you can upgrade it!
"It's a little unrealistic to rub an aircraft carrier with your hands for the time being, but isn't it easy to rub a lens?"
So starting from rubbing the lens by hand, far-leading technologies were introduced one after another.
"What do you think is a strong country?"
"The enemy retreated thousands of miles and did not dare to cross the pond."
“People all over the world are learning Chinese, translating Chinese papers, and reading instructions are all in Chinese characters.”
"I am a street sweeper. All I know is that Master Kang has made things cheaper for us, and we can never spend all the money we have. Everyone is happy, so with him, the country is strong!"