Question

    Many people feel that dream is unique to humans. However, many dog owners will likely disagree on that. They have noticed that their dogs at various times during the sleep may shake legs, snort (哼) and sometimes growl (低声吼叫) which gives the impression that they are dreaming. These things may wonder us about whether dogs dream.

Scientists confirm that dogs probably do dream. It turns out that dog brains and human brains have many similarities during sleep cycles. Researchers used special machines to measure electrical activity in a dog’s brain and human’s brain. Scientists already knew that when humans dream, a certain part of the brain is active during sleep. Researchers discovered that the same part of the brain is active in sleeping dogs. Scientists have other data that back up these findings.

Many people dream that they are trying to move but cannot. Interestingly, part of that experience is not a dream. When people sleep, the brain produces a chemical that causes the dreamer to become temporarily paralyzed (使麻痹). Researchers think this happens so that people cannot physically act out dreams while they are sleeping. Dog brains make the same chemical. In one study during which this chemical was blocked, sleeping test dogs performed physical activities, such as standing up, sniffing around the room for imaginary rabbits, or chasing imaginary balls.

Because of these similarities, researchers believe that the content of a dog’s dream might come from the same source as a human’s dream. “People’s dreams are usually based on things they did that day,” says Dr. Samantha Hudspith. “So there is reason to believe that dogs dream about the things they’ve done that day. Of course, there will never be a way to prove this. Dogs cannot describe their dreams the way that humans can.”

1.What does the underlined phrase “back up” mean in the second paragraph?

A.Disagree. B.Support.

C.Record. D.Show.

2.What happened to a sleeping dog when this chemical mentioned in paragraph 3 was cut off?

A.It woke up. B.It stopped dreaming.

C.It acted out its dream. D.It couldn't move its body.

3.How is the text mainly developed?

A.By telling stories B.By giving examples.

C.By comparing details D.By listing differences.

4.What is the best title for the text?

A.Do Dogs Dream? B.Why Do Dogs Dream?

C.Signs of Dog Dreams D.Similarities Between Humans and Dogs

Answer

1.B

2.C

3.C

4.A

【解析】

本文是一篇说明文。许多人觉得梦是人类独有的。然而许多养狗人注意到狗在睡眠时会摇晃腿、打鼾、有时会低声吼叫，因此他们认为狗在做梦。科学家通过实验发现狗可能会做梦，但也无法证明这一点，因为狗无法像人类那样描述自己的梦。

1.词义猜测题。根据第二段中的“Scientists confirm that dogs probably do dream.”可知，科学家证实狗可能会做梦。下文的研究结果是在解释为什么狗有可能像人一样做梦。由本段最后一句“Scientists have other data that back up these findings.”可知，科学家有其他数据支持这些研究结果。因此本段首尾两句相扣，back up与confirm同义，意为“证明，证实”。A. disagree不同意；B. support支持。C. record记录；D. show展示。因此，通过对confirm的理解，选择support合适，即有数据支持这些研究成果。故选B。

2.推理判断题。根据第三段中的“In one study during which this chemical was blocked, sleeping test dogs performed physical activities, such as standing up, sniffing around the room for imaginary rabbits, or chasing imaginary balls.”可知，在一项研究中阻断这种化学物质的产生，结果是参与睡眠测试的狗开始进行身体活动，例如站起来，在房间里嗅想象中的兔子，或者追逐想象中的球。即当该种化学物质被抑制后，睡着的狗开始将梦中的活动付诸于实施。故选C。

3.推理判断题。根据第二段中的“It turns out that dog brains and human brains have many similarities during sleep cycles.”和第三段中的“Dog brains make the same chemical.”可知，狗的大脑和人的大脑在睡眠时发生的活动有许多相似之处，狗的大脑和人的大脑产生同样的化学物质。因此本文主要是通过“比较”的方法来写作的。故选C。

4.主旨大意题。根据第一段 “Many people feel that dream is unique to humans. However, many dog owners will likely disagree on that. They have noticed that their dogs at various times during the sleep may shake legs, snort and sometimes growl which gives the impression that they are dreaming. These things may wonder us about whether dogs dream.”可知，许多人觉得梦是人类独有的。然而，许多养狗人可能会在这一点上意见不一。他们注意到，他们的狗在睡眠中的不同时间可能会摇晃腿、打鼾，有时会低声吼叫，这给人一种他们在做梦的印象。这些事情可能会让我们怀疑狗是否会做梦。由下文“Scientists confirm that dogs probably do dream.”可知，文章就狗是否会做梦展开论述。根据文章最后“So there is reason to believe that dogs dream about the things they’ve done that day. Of course, there will never be a way to prove this. Dogs cannot describe their dreams the way that humans can.”可知，有理由相信狗梦见了他们当天所做的事情。当然，永远不会有办法证明这一点。狗无法像人类那样描述自己的梦。因此用问句“狗是否能做梦？”来总结文章主要内容是合适的，即它是文章的最佳标题。故选A。