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.
____
[单选题]The history of transportation is very long and full of changes and inventio
[单选题]The history of transportation is very long and full of changes and inventio
[单选题]The history of transportation is very long and full of changes and inventio
[单选题]The history of transportation is very long and full of changes and inventio
[单选题]The history of transportation is very long and full of changes and inventio
[单选题]The history of transportation is very long and full of changes and inventio
[单选题]The history of transportation is very long and full of changes and inventio
[单选题]The history of transportation is very long and full of changes and inventio
[单选题]The history of transportation is very long and full of changes and inventio
[单选题]These glass wares are too _____ to survive long transportation by land.A.fa