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The mark test (or “mirror test”) is often seen as a good way to learn if an animal is aware of itself — one sign of how smart an animal is. The list of animals that 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 had passed the test.

But some scientists believe the mark test doesn’t work well for all animals. Roosters are a good example. Scientists at the University of Bonn in Germany recently ran the mark test on roosters. They put a pinkish triangle on the chest of the roosters. But when the roosters looked in a mirror, they didn’t seem to notice the mark.

The scientists 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 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 the bird and watching how the rooster reacted. When there was no mirror, the roosters reacted as usual: they called out when they were near another rooster, but remained quiet when they were 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 despite the hawk shadow. It did this even if there was a rooster hidden behind the mirror.

The scientists hope their results will encourage other scientists to look for better ways of testing self-recognition in animals. It may turn out that some kinds of animals are more intelligent than people thought.

1.Which of the following didn’t pass the mark test?

A Roosters.

B Dolphins.

C Chimpanzees.

D Elephants.

解析：选A。A 细节理解题。根据第一段最后一句可知，通过“标记测试”的动物通常是大脑较大的动物，比如海豚、黑猩猩和大象；结合第二段内容可知，一些科学家认为“标记测试”并不适用于公鸡，并根据第二段最后一句可知，公鸡没有通过这个测试。故选A。

2.What can we learn about roosters from Paragraph Three?

A They like to make loud calls.

B They make cries when alone.

C They warn each other of danger.

D They keep quiet when there’s danger.

解析：选C。C 细节理解题。根据第三段中的“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.”可知，当有危险时——比如鹰飞过——公鸡会发出响亮的叫声来警告附近的鸡。但公鸡只有在其他鸡能听到的情况下才会叫。如果它们是单独的，它们会保持安静，这样鹰就不会看到它们。由此可知，公鸡会相互之间提醒危险。故选C。

3.What can be known from the test of using a hawk shadow?

A Roosters didn’t react to the shadow of a hawk.

B Roosters recognized themselves in a mirror.

C Roosters saw the rooster hidden behind the mirror.

D Roosters were smart enough to pass the mark test.

解析：选B。B 推理判断题。根据第四段内容可知，当一只公鸡在镜子里可以看到自己时，它不会误以为有另一只公鸡。尽管有鹰的影子，它仍然沉默。由此可见，公鸡知道镜子里是自己而并非其他的鸡，即它们能认出镜子里的自己。故选B。

4.What’s the purpose of the text?

A To criticize the mark test on roosters.

B To describe a group of researchers.

C To explain behaviors of some chickens.

D To present a scientific test on roosters.

解析：选D。D 推理判断题。结合本文大意：以前科学家们用常规的“标记测试”来测试公鸡能否认出镜子中的自己，但一些科学家借助鹰影对公鸡进行测试，发现公鸡其实能够认出镜子里的自己。由此可知，本文主要展示一项关于公鸡的科学测试。故选D。