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Scientists recently discovered that pictures on cave walls at Creswell Crags are the oldest known in Great Britain. But they didn’t find out in the usual way.
Archaeologists often date cave art with a process called radiocarbon dating.The technique can measure the age of carbon found in charcoal(木炭)drawings or painted pictures.Carbon is an element(成分) found in many things, including charcoal and even people.But in this case, there was no paint or charcoal to test.People carved the pictures of animals and figures into the rock using stone tools.The scientists had an“aha！”moment when they noticed small rocks stuck to the top of the drawings.The small rocks must have formed after the drawings were made.
“It is rare to be able to scientifically date rock art，” said Alistair Pike，an archaeological scientist at Britain’s University of Bristol.“We were very fortunate that some of the engravings(雕刻) were covered by stalagmites(石笋)．”
When a test proved that the stalagmites formed 12，800 years ago，the scientists knew the art underneath them had to be at least that old.And some of the animals shown，like the European bison，are now extinct—another tipoff(征兆) that the art is quite old.
The artists came to Creswell Crags.This place is one of the farthest points north reached by our ancient ancestors during the Ice Age.At that time，much of the North Sea was dry，so people could move about more easily.
Some tools and bones found there are 13，000 to 15，000 years old.They show that the travelers hunted horses，reindeer, and arctic hares.Their artwork is similar to art in France and Germany.It tells scientists that the Creswell Crags artists must have had a close connection to peoples several thousand kilometers away—another important evidence of understanding how humans spread out across the world.
【解题导语】 本文是一篇说明文，带领我们探寻英国古老的洞窟美术的历史。
1．Why do scientists say the art is quite old?
A．The art was carved into stone with stone tools.
B．Most animals carved in the stone are extinct.
C．The cave is one of the farthest points in the world.
D．Some pictures were covered by stalagmites more than 10，000 years old.
D 解析：细节理解题。根据倒数第三段可知答案。
2．By studying the cave art，scientists could learn about ________．
A．how ancient people crossed the North Sea
B．why some of the animals have died out
C．how humans spread out across the world
D．what ancient people had for food at that time
C 解析：细节理解题。根据最后一段最后一句“another important evidence of understanding how humans spread out across the world”可知。
3．Which of the following can be the best title for the text?
A．Cave Art About Animals Is Most Beautiful
B．Cave Art Is Found in an Unusual Way
C．Cave Art Turns Out to Be Britain’s Oldest
D．Cave Art Has a Great Influence on Britain
C 解析：标题归纳题。本文主要介绍Creswell Grags的洞窟艺术为什么是英国最古老的艺术，后半部分给出了证据。
