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When Henry Ford put an engine on a horse carriage, he had no idea that his simple invention would revolutionize the world. Read about how an everyday part of our lives started with a single, simple concept. -
Nothing can capture attention like the thrill and rush of roller coasters. Your students will learn how the force of gravity makes their favorite roaring rollers move. -
Los trenes fueron una de las primeras formas mecanizadas en que los humanos solían viajar largas distancias. Los lectores verán cómo cambiaron la forma del país al transportar humanos y suministros de costa a costa.
