Question

【題目】 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(神經元). In rat and mouse studies, Baram’s group saw that the release(釋放) 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】

這是一篇說明文。主要介紹了科學家關于壓力對人的記憶的影響的研究，長期的壓力會導致記憶損失，但最新的研究發(fā)現，短期的壓力也會對記憶造成損害，引起記憶的損失并分析了原因。

【1】細節(jié)理解題。根據第一段中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，長期的壓力會損害人的記憶，短期的壓力也有同樣的結果。故選A項。

【2】詞義猜測題。根據第四段中In rat and mouse studies, Baram’s group saw that the release(釋放) 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，在老鼠的實驗中，釋放CRH會導致樹突棘的迅速分裂，進而限制了突觸收集和儲存記憶的能力；再根據最后一段中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，在第二個實驗中科學家通過保持少量CRH，來觀測神經元的________情況。故畫線部分的意思和break up(分解)相近。C項broke apart（分解）與此相近。故選C項。

【3】推理判斷題。根據文章第一段的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，一項研究表明，持續(xù)數周或數月的嚴重壓力會損害大腦記憶區(qū)域的細胞通訊。最近，加州大學歐文分校的研究人員首次證明，持續(xù)數小時的短期壓力也有同樣的效果。所以作者寫作的主要目的是介紹一項關于壓力會對記憶力造成損害的發(fā)現。C項To introduce a new finding about stress.(為了介紹一項關于壓力的新發(fā)現)是作者的寫作目的。故選C項。