The wheelbarrow is a great invention. It made it easier to lift heavy objects and could hold lots of stuff at the same time. The wheelbarrow was invented in China and helped with carrying the dead or bringing injured people to safety. It would also save money because it made it easier to lift things, and it saved time so people would not have to pay their slaves as much.
Gears are used for many things such as the clock and mills. If there were no clocks you would have to go outside and look at the sun to figure out what time it was, and if it was cloudy you could not see the sun. There are digital clocks now that do not have any gears so we don’t need to go outside – thank goodness!