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A new study suggests that roosters can recognize themselves in a mirror(镜子).
Scientists use the “mark test” to test whether an animal can recognize itself. A mark is put on an animal, usually in a spot that can only be seen in a mirror. Then the animal is allowed to look in a mirror. If the animal seems to pay attention to the mark, scientists believe the animal has recognized itself.
The list of animals who can recognize themselves in a mirror isn’t long. The skill has mainly been found in animals with large brains, like dolphins, chimpanzees and elephants. Until recently, only one kind of bird has passed the test.
Scientists at the University of Bonn in Germany recently ran the mark test on roosters. They put a pink triangle(三角形) on the chests of the roosters. But when the roosters looked in a mirror, they didn’t seem to notice the mark.
The scientists then needed a different way to test whether the roosters could recognize themselves.
When there’s danger—like a hawk(鹰) flying above—roosters make loud calls to warn nearby chickens. But roosters only make the cries if other chickens can hear them. If they’re alone, they remain quiet so the hawk won’t see them.
The scientists realized that they could use the shadow(影子) of a hawk to test whether or not the roosters thought they were alone—even when they could see “another” chicken in a mirror.
First, the scientists let the roosters spend time getting used to being in a closed - in space and having a mirror around. Then, they ran several tests by making a hawk shadow appear above a rooster and watching how it reacted. When there was no mirror, the roosters reacted as usual. It called out when it was near another rooster (Picture ▲ ), but remained quiet when it was alone. But when a rooster was in a space where it could see itself in the mirror, it wasn’t fooled into thinking there was another rooster. It remained silent under the hawk shadow. It did this even if there was a rooster hidden behind the mirror.
The scientists say the results show that the roosters knew they were seeing themselves in the mirror, and not other roosters.
18. What is the purpose of the “mark test”?
A. To test a bird’s ability to fly.
B. To measure an animal’s brain size.
C. To see if an animal can recognize itself.
D. To compare different animals’ intelligence.
19. What does the underlined word “them” refer to?
A. Hawks.
B. Roosters.
C. Dolphins.
D. Scientists.
20. Which of the following pictures can be put into “▲ ”?
21. What can we infer from the passage?
A. Roosters prefer to make no sounds when they face danger alone.
B. Roosters are not as smart as dolphins, chimpanzees and elephants.
C. The mark test can’t tell if an animal can recognize itself in the mirror.
D. When seeing its image in the mirror, the rooster thinks there’s another rooster.
A new study suggests that roosters can recognize themselves in a mirror(镜子).
Scientists use the “mark test” to test whether an animal can recognize itself. A mark is put on an animal, usually in a spot that can only be seen in a mirror. Then the animal is allowed to look in a mirror. If the animal seems to pay attention to the mark, scientists believe the animal has recognized itself.
The list of animals who can recognize themselves in a mirror isn’t long. The skill has mainly been found in animals with large brains, like dolphins, chimpanzees and elephants. Until recently, only one kind of bird has passed the test.
Scientists at the University of Bonn in Germany recently ran the mark test on roosters. They put a pink triangle(三角形) on the chests of the roosters. But when the roosters looked in a mirror, they didn’t seem to notice the mark.
The scientists then needed a different way to test whether the roosters could recognize themselves.
When there’s danger—like a hawk(鹰) flying above—roosters make loud calls to warn nearby chickens. But roosters only make the cries if other chickens can hear them. If they’re alone, they remain quiet so the hawk won’t see them.
The scientists realized that they could use the shadow(影子) of a hawk to test whether or not the roosters thought they were alone—even when they could see “another” chicken in a mirror.
First, the scientists let the roosters spend time getting used to being in a closed - in space and having a mirror around. Then, they ran several tests by making a hawk shadow appear above a rooster and watching how it reacted. When there was no mirror, the roosters reacted as usual. It called out when it was near another rooster (Picture ▲ ), but remained quiet when it was alone. But when a rooster was in a space where it could see itself in the mirror, it wasn’t fooled into thinking there was another rooster. It remained silent under the hawk shadow. It did this even if there was a rooster hidden behind the mirror.
The scientists say the results show that the roosters knew they were seeing themselves in the mirror, and not other roosters.
18. What is the purpose of the “mark test”?
A. To test a bird’s ability to fly.
B. To measure an animal’s brain size.
C. To see if an animal can recognize itself.
D. To compare different animals’ intelligence.
19. What does the underlined word “them” refer to?
A. Hawks.
B. Roosters.
C. Dolphins.
D. Scientists.
20. Which of the following pictures can be put into “▲ ”?
21. What can we infer from the passage?
A. Roosters prefer to make no sounds when they face danger alone.
B. Roosters are not as smart as dolphins, chimpanzees and elephants.
C. The mark test can’t tell if an animal can recognize itself in the mirror.
D. When seeing its image in the mirror, the rooster thinks there’s another rooster.
答案
18. C
19. B
20. B
21. A
19. B
20. B
21. A
