Sheep, like turkeys and ostriches, are not considered the cleverest animals. British scientists said last Wednesday human may have underestimated(低估) the woolly creatures. They could be much smarter than we think.
Researchers at the Babraham Institute in Cambridge, southern. England, have shown that animals have a good memory system and are extremely good at recognizing faces--which they think is a sure sign of intelligence.
Behavioral scientist Keith Kendrick and his friends trained 20 sheep to recognize and distinguish(区别) 25 pairs of sheep faces and used electrodes(电极) to measure their brain activity, which showed they could remember 50 faces for up to two years.
"If they can do that with faces, the fact is that they have to have reasonable intelligence, otherwise, what is the point of having a system for remembering anything else," Kendrick said in an interview.
So hours of seemingly mindless eating grass may not be so mindless after all.
Kendrick believes sheep got their reputation as dumb animals because they live in large groups and do not appear to have much ind
ividuality and are frightened of just about everything.
All animals, including humans, once they are frightened don't tend to show signs of intelligent action," he explained.
In research reported in the science journal Nature, Kendrick and his team showed that sheep, like humans, have a specialized system in the brain, which allows them to distinguish between many different faces that look extremely similar.
"The most important findings of the study is that they are able, both from a behavioral point of view and from looking at the way the brain is organized, to remember a large number of faces of individuals for a very long time," said Kendrick. "It is a very strange system. They are showing similar abilities in many ways to humans. "
From the first paragraph we can find that ______.

A．people used to think sheep are smarter than the other animals

B．people used to raise sheep in a wrong way

C．people don't consider sheep as clever animals

D．people have done a lot of research on sheep

From what Kendrick said in the interview we learn that ________.

A．scientists have learned a lot about sheep's intelligence

B．scientists have learned little about sheep's intelligence

C．scientists can't do anything more about sheep's memory

D．scientists don't have to research animals' memory

As is shown in the passage _________.

A．sheep are among the weak animals

B．it is not right for people to raise sheep in groups

C．when sheep eat grass in the fields their minds may be active

D．if people feel frightened, they may become more brave

When scientists found that sheep show similar abilities in many ways to humans they may think it _____.

A．worrying

B．moving

C．frightening

D．interesting