Question

    All animals—from humans to birds，worms and crocodiles—sleep，however，not all species sleep alike. Scientists have long puzzled over which aspects are truly fundamental. Now a new study on lizards(蜥蜴)suggests that sleep states once thought to occur only in mammals and birds have much older evolutionary origins.

Scientists had long doubted that birds and mammals are the only vertebrates(脊椎动物)to experience rapid eye movement(REM)，a sleep state in which the body is mostly immobile but the brain is overworking. During REM sleep，the brain produces high-frequency waves of electrical activity and the eyes turn suddenly from time to time. In humans，REM is closely linked to dreaming. REM is a pattern of slow-wave sleep，a state in which brain activity weakens and the waves become more consistent. This slower state is widely thought to be important to memory formation and storage.

“But scientists who looked for signs of REM and slow-wave sleep in reptiles(爬行动物) have had‘confusing’results，”says Gilles Laurent，a neuroscientist at the Max Planck Institute for Brain Research in Frankfurt，Germany. So he and his colleagues had planned to examine how the lizards—a common pet in Germany use visual information to chase treats. Using camera，the team found that the sleeping lizards’eyes twitched during the REM-like stage，just like other animals. They also found a very familiar pattern within the slower phase of the lizards’brain waves. Some scientists believe these waves help transform new information into memories by replaying past events quickly.

Although more studies are still needed to determine whether the function of these brain wave patterns is the same across species，the results suggest that these REM and slow-wave sleep patterns could date all the way back to the common ancestor of reptiles，birds，and mammals.

1.What does paragraph 2 mainly talk about?

A.The origin of human dream.

B.The definition and effect of REM.

C.The features and course of memory.

D.The advantages and disadvantages of REM.

2.Which of the following can best replace the underlined word“twitched”in paragraph 3 ?

A.opened wide B.moved quickly

C.stayed closed D.kept still

3.How does the lizards’brain waves turn information into memories according to some scienfists?

A.By increasing their frequency slowly.

B.By changing their pattern occasionally.

C.By playing back the past events quickly.

D.By connecting visual information effectively.

4.What can we infer from the last paragraph?

A.The function of the brain wave is the same.

B.All the animals have the common ancestor.

C.The sleep pattern of all the animals is the same.

D.The study about sleep pattern has a long way to go.

Answer

1.B

2.B

3.C

4.D

【解析】

本文是一篇说明文。所有的动物-从人类到鸟类-蠕虫和鳄鱼-都睡眠，然而，并不是所有的物种睡眠一样。文章通过介绍一项研究，讲述了曾经被认为只发生在哺乳动物和鸟类身上睡眠有更古老的进化起源。

1.主旨大意题。根据第二段的“ rapid eye movement(REM)，a sleep state in which the body is mostly immobile but the brain is overworking.(REM ,一种睡眠状态，身体大多不动，但大脑过度工作。)”以及下文内容对REM睡眠状态的解释说明可推断，本段主要介绍了什么是REM的定义和影响。故选B。

2.词义猜测题。根据划线句上文“So he and his colleagues had planned to examine how the lizards—a common pet in Germany use visual information to chase treats.(因此，他和他的同事计划研究蜥蜴-德国一种常见的宠物-如何利用视觉信息来寻追逐猎物。)”可知，划线句说的是这个团队使用相机，发现睡眠中的蜥蜴的眼睛在类似REM期间抽动，就像其他动物。故划线词语B项意义相近。故选B。

3.细节理解题。根据倒数第二段最后一句“Some scientists believe these waves help transform new information into memories by replaying past events quickly.”可知，一些科学家认为，这些电波通过快速回放过去的事件，帮助将新的信息转化为记忆。C项“通过快速回放过去的事件”正确。故选C。

4.推理判断题。根据最后一段的“Although more studies are still needed to determine whether the function of these brain wave patterns is the same across species”可知，还需要更多的研究来确定这些脑电波模式在不同物种间的功能是否相同，因此推断关于睡眠模式的研究还有很长的路要走。故选D。