1. D
2. B
3. C
4. C
5. D
6. A
7. D
8. C
9. B
10. C

Fill in blank II

It is still unknown who invented the wheel, and when and why it was invented. According to some archaeologists, it was probably originally invented about 8000 BC. The wheel was almost certainly independently invented in Mesopotamia – present – day Iraq. An oldest drawings with wheeled carts date from about 3000 BC. Though we all know that the wheel may have been in use for millennia before these drawings were made. But there is also evidence from the same period of time that wheels were used for the productivity of pottery. Most recently, the oldest-know wooden wheel in the world was found in Slovenia. The invention of the wheel revolutionized activities as disparate as transportation, war, and the production of pottery for which it may have been first used. It did not use a long time to discover that wheeled wagons could be used to carry heavy loads and fast potters’ wheels enabled early mass production of pottery. But that is the use of the wheels as a transformer of energy that revolutionized the application of nonhuman power sources.