history review lesson 20

gears: if did not have gears we would not have modern day stuff gears are in cars, trains, tv. if we didn’t have gears instead of cars we had to ride horses or walk. it may seem impossible but grasshoppers have bone like gear legs. if a grasshopper jumps he winds up and he’s gone. waterwheels: waterwheels have a crank hooked up to it so for example in a river there is a waterwheel. it goes to a big pond waterwheels transfer water from place to place. now a days waterwheels are fully auto matic. but in the old days people had to spin the crank for the waterwheel to spin.