Question

【题目】 A study has shown that severe stress lasting weeks or months can damage cell communications in the brain’s memory areas. Recently, researchers from University of California, Irvine, have provided the first evidence that short-term stress lasting for a few hours has the same effect.

“Stress does exist in our lives and cannot be avoided,” said Dr. Baram, leader of the UC Irvine School. “Our findings can play an important role in the present development of medicine that might prevent these undesirable effects and offer understanding of why some people are forgetful or have difficulty keeping the memories.”

In their study, Baram and her UC Irvine colleagues identified a novel process in which stress caused these effects. They found that, severe stress activated(激活) Corticotropin Releasing Hormones(CRH), which prevented the brain from keeping memory.

Memory takes place at synapses, where there are connections through which brain cells communicate. These synapses lie on dendritic spines(神经元). In rat and mouse studies, Baram’s group saw that the release(释放) of CRH in the brain’s primary memory center led to the rapid breakup of these dendritic spines, which in turn limited the ability of synapses to collect and store memories.

In addition, the researchers reproduced the effects of stress on dendritic spines by keeping low levels of CRH, and watching how the spines ruptured over minutes. “Fortunately, once we removed the CRH, the spines seemed to grow back again, ” Baram said. “And this study can play a role in the creation of treatments to address stress-related memory loss.”

【1】According to the text, short-term stress can lead to ________.

A.memory lossB.cell decrease

C.head damageD.thought disorder

【2】The underlined word “ruptured” in Paragraph 5 is closest in meaning to ________.

A.came into beingB.built up

C.broke apartD.died away

【3】What is the author’s purpose of writing the text?

A.To discuss the main stages of stress.

B.To show the primary cause of stress.

C.To introduce a new finding about stress.

D.To promote an effective treatment for stress.

Answer 1

【答案】

【1】A

【2】C

【3】C

【解析】

这是一篇说明文。主要介绍了科学家关于压力对人的记忆的影响的研究，长期的压力会导致记忆损失，但最新的研究发现，短期的压力也会对记忆造成损害，引起记忆的损失并分析了原因。

【1】细节理解题。根据第一段中A study has shown that severe stress lasting weeks or months can damage cell communications in the brain memory areas和that short-term stress lasting for a few hours has the same effect.可知，长期的压力会损害人的记忆，短期的压力也有同样的结果。故选A项。

【2】词义猜测题。根据第四段中In rat and mouse studies, Baram’s group saw that the release(释放) of CRH in the brain’s primary memory center led to the rapid breakup of these dendritic spines, which in turn limited the ability of synapses to collect and store memories.可知，在老鼠的实验中，释放CRH会导致树突棘的迅速分裂，进而限制了突触收集和储存记忆的能力；再根据最后一段中In addition, the researchers reproduced the effects of stress on dendritic spines by keeping low levels of CRH, and watching how the spines ruptured over minutes.可知，在第二个实验中科学家通过保持少量CRH，来观测神经元的________情况。故画线部分的意思和break up(分解)相近。C项broke apart（分解）与此相近。故选C项。

【3】推理判断题。根据文章第一段的A study has shown that severe stress lasting weeks or months can damage cell communications in the brain’s memory areas. Recently, researchers from University of California, Irvine, have provided the first evidence that short-term stress lasting for a few hours has the same effect.可知，一项研究表明，持续数周或数月的严重压力会损害大脑记忆区域的细胞通讯。最近，加州大学欧文分校的研究人员首次证明，持续数小时的短期压力也有同样的效果。所以作者写作的主要目的是介绍一项关于压力会对记忆力造成损害的发现。C项To introduce a new finding about stress.(为了介绍一项关于压力的新发现)是作者的写作目的。故选C项。