It must have been a very clever human who looked at a sheep walking past and thought of the use its wool might have!
The oldest surviving textile（纺织品） made out of wool is around 3，500years old．Wool was probably the first fiber to be woven into textiles．Because when humans stopped hunting and started raising animals，it was their first step from a wild life to a civilized one．Sheep became a convenience store for the new lifestyle of our ancestor during the Stone Age，a walking food supply that required little care．Sheep provided all---meat and milk for food，skin and bones for clothing，shelters and tools．
Some sheep were suitable to roast while others were to produce wool，as sheep fit for eating do not necessarily have high-quality wool．Early wild species of sheep had long outer hair protecting their short wool undercoats．It was this underlayer that was highly suitable for textile use，so they were selectively bred into modern sheep．
Great empires were built on the backs of sheep and their wool．Around 1800BC，the civilization of Babylonia was famous for its wool．After the Romans conquered Spain，they developed a new breed that would come to be known as Spanish Merino，with the whitest，finest wool ever known．Today，the Merino is the most highly regarded breed in the world．
The Chinese held onto the secret of silk for thousands of years before Europeans even got an idea about how to put two threads together．With wool， they seem to have got their revenge．



What do we know about raising sheep in the Stone Age？ ______

A. People made great efforts to raise sheep．
B. People exchanged sheep for what they needed．
C. Sheep led to the boom of ancient society．
D. Sheep met many basic needs of ancient people．

What is the main idea of Paragraph 3？ ______

A. Economic value of sheep．
B. Features of sheep breeds．
C. Choice of suitable sheep breeds．
D. Development of the wool industry．

What are Babylonia and the Romans mentioned to prove？ ______

A. The wisdom of ancient people．
B. The aggression of ancient nations．
C. The link between their rise and wool．
D. The greatness of well-organized ancient society．

What does the underlined part in the last paragraph mean？ ______

A. They lost their advantage of something．
B. They won and got rid of the shame of failure．
C. They did something harmful to their opponent．
D. They were taking pains to catch up with others．