The history of transportation is very long and full of changes and inventions.It starts (1) _____ walking, which is not any invention; it just takes energy.People used to walk to get to other places.If you wanted to get somewhere quickly, the (2) _____ way to do that was to run.Actually, the first invention for the transportation (3) _____ was the shoe.Centuries ago there were no shoes, and people walked barefoot.

　　Then people invented (4) _____ to transport themselves and materials from one place to another.In some cultures, people invented sledges(雪橇), (5) _____ are a kind of board that you drag along the ground.You can tie things on the sledges to help carry them, but it’s a challenging invention (6) _____ if you hit a rock with the sledges as you pull it, the contents can (7) _____.In other cultures, people invented the wheels, which they used to make it easier to move things—and people.That was the beginning of many innovations in transportation.

　　(8) _____ people had wheels they could invent other ways to travel.They could put the wheels on a board and make it a wagon, and then they could (9) _____ that wagon to an ox or a horse and ride as well as carry materials.That wheel led to (10) _____ we have today: trucks, automobiles, and even boats and planes.For example, there were steamboats that used giant wheels that turned with blades, pushing the water and pushing the boat forward.
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