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 transportation（3）was the shoe. Centuries ago there were no shoes, and people walked barefoot.
　　Then people invented（4）to transport themselves and material from one place to another. In some culture, people invented sledges(雪橇)，（5）are a kind of board that you drag along the ground. You can tie things on the sledge to help carry them, but it′s a challenging invention（6）if you hit a rock with sledge as you pull it, the contents can（7）. In other cultures, people invented the wheel, 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 wheel on a board and make it 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.

　　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 transportation（3）was the shoe. Centuries ago there were no shoes, and people walked barefoot.
　　Then people invented（4）to transport themselves and material from one place to another. In some culture, people invented sledges(雪橇)，（5）are a kind of board that you drag along the ground. You can tie things on the sledge to help carry them, but it′s a challenging invention（6）if you hit a rock with sledge as you pull it, the contents can（7）. In other cultures, people invented the wheel, 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 wheel on a board and make it 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.

　　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 transportation（3）was the shoe. Centuries ago there were no shoes, and people walked barefoot.
　　Then people invented（4）to transport themselves and material from one place to another. In some culture, people invented sledges(雪橇)，（5）are a kind of board that you drag along the ground. You can tie things on the sledge to help carry them, but it′s a challenging invention（6）if you hit a rock with sledge as you pull it, the contents can（7）. In other cultures, people invented the wheel, 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 wheel on a board and make it 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.

　　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 transportation（3）was the shoe. Centuries ago there were no shoes, and people walked barefoot.
　　Then people invented（4）to transport themselves and material from one place to another. In some culture, people invented sledges(雪橇)，（5）are a kind of board that you drag along the ground. You can tie things on the sledge to help carry them, but it′s a challenging invention（6）if you hit a rock with sledge as you pull it, the contents can（7）. In other cultures, people invented the wheel, 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 wheel on a board and make it 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.

　　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 transportation（3）was the shoe. Centuries ago there were no shoes, and people walked barefoot.
　　Then people invented（4）to transport themselves and material from one place to another. In some culture, people invented sledges(雪橇)，（5）are a kind of board that you drag along the ground. You can tie things on the sledge to help carry them, but it′s a challenging invention（6）if you hit a rock with sledge as you pull it, the contents can（7）. In other cultures, people invented the wheel, 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 wheel on a board and make it 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.

　　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 transportation（3）was the shoe. Centuries ago there were no shoes, and people walked barefoot.
　　Then people invented（4）to transport themselves and material from one place to another. In some culture, people invented sledges(雪橇)，（5）are a kind of board that you drag along the ground. You can tie things on the sledge to help carry them, but it′s a challenging invention（6）if you hit a rock with sledge as you pull it, the contents can（7）. In other cultures, people invented the wheel, 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 wheel on a board and make it 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.