题目

Directions: There are two passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A), B), C) and D). You should decide on the best choice.The Mariana Trench(马里亚纳海沟) in the northern Pacific is the deepest part of the world's oceans. You might think a place that remote would be untouched by human activity. At its deepest the water in the trench is near freezing and the pressure would crush a human like a bug. But it is polluted.Scientists have only recently explored it. Among them is biologist Alan Jamieson of Newcastle University in England. His team dropped what they call a mechanical "lander" down into the trench. It had cameras and water samplers and some baited traps.When the lander surfaced, the traps contained amphipods(片脚类动物) -- shrimp like crustaceans(甲壳动物).The amphipods were contaminated with toxic chemicals used for decades in industry, as well as other industrial pollutants known as persistent organic pollutants. "Every sample we had," Jamieson says, "had contaminants in it at very high or extraordinarily high levels."How high? He compared the contamination level in his Mariana amphipods to crabs living in waters fed by one of the most polluted rivers, as well as amphipods from other parts of the world. He says, "And what we were finding in the deepest place in the world were (levels) hugely higher, 50 times in some cases." He thinks the pollutants might get to the trenches by holding on to plastic that's floating in the ocean. Fish and other marine animals absorb pollutants as well. Eventually, the plastic and the dead animals fall to the bottom. Like dirt in your house, a lot of it will collect at the lowest points. It's simply a matter of gravity.Marine biologist Katherine Dafforn at the University of New South Wales in Australia says the discovery of such high levels of toxic chemicals in these trenches is "disturbing". She says, "A lot of chemicals will have far-reaching impacts that we don't necessarily know about." And those impacts might be in places that people don't pay much attention. Jamieson says just because pollution is out of sight doesn't mean it's harmless. "We've got to remember, planet Earth is mostly deep sea, and to think that it's OK just to ignore it is a little bit irresponsible.What do we learn about the Mariana Trench?A. It is the center of the world's ocean.B. It has been affected by contamination.C. It remains untouched by human activity.D. It has been profoundly explored by scientists.

Directions: There are two passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A), B), C) and D). You should decide on the best choice.The Mariana Trench(马里亚纳海沟) in the northern Pacific is the deepest part of the world's oceans. You might think a place that remote would be untouched by human activity. At its deepest the water in the trench is near freezing and the pressure would crush a human like a bug. But it is polluted.Scientists have only recently explored it. Among them is biologist Alan Jamieson of Newcastle University in England. His team dropped what they call a mechanical "lander" down into the trench. It had cameras and water samplers and some baited traps.When the lander surfaced, the traps contained amphipods(片脚类动物) -- shrimp like crustaceans(甲壳动物).The amphipods were contaminated with toxic chemicals used for decades in industry, as well as other industrial pollutants known as persistent organic pollutants. "Every sample we had," Jamieson says, "had contaminants in it at very high or extraordinarily high levels."How high? He compared the contamination level in his Mariana amphipods to crabs living in waters fed by one of the most polluted rivers, as well as amphipods from other parts of the world. He says, "And what we were finding in the deepest place in the world were (levels) hugely higher, 50 times in some cases." He thinks the pollutants might get to the trenches by holding on to plastic that's floating in the ocean. Fish and other marine animals absorb pollutants as well. Eventually, the plastic and the dead animals fall to the bottom. Like dirt in your house, a lot of it will collect at the lowest points. It's simply a matter of gravity.Marine biologist Katherine Dafforn at the University of New South Wales in Australia says the discovery of such high levels of toxic chemicals in these trenches is "disturbing". She says, "A lot of chemicals will have far-reaching impacts that we don't necessarily know about." And those impacts might be in places that people don't pay much attention. Jamieson says just because pollution is out of sight doesn't mean it's harmless. "We've got to remember, planet Earth is mostly deep sea, and to think that it's OK just to ignore it is a little bit irresponsible.What do we learn about the Mariana Trench?
  • A. It is the center of the world's ocean.
  • B. It has been affected by contamination.
  • C. It remains untouched by human activity.
  • D. It has been profoundly explored by scientists.

题目解答

答案

B

解析

本题考查对文章细节的理解能力，需要结合选项与原文对应信息进行判断。核心要点在于识别马里亚纳海沟被污染的关键描述。文章明确指出，尽管海沟位置偏远、环境极端，但科学家发现这里的生物体内含有高浓度污染物，说明人类活动的影响已波及此处。解题关键是排除干扰项，抓住“污染”这一核心信息。

选项分析

选项B（正确）

文章多次提到海沟受到污染：

  1. “But it is polluted.”（但这里已被污染）
  2. “amphipods contaminated with toxic chemicals”（片脚类动物被有毒化学物质污染）
  3. “contaminants in it at very high or extraordinarily high levels”（污染物浓度极高）
    这些信息直接对应选项B中的“affected by contamination”。

选项A（错误）

文章明确指出马里亚纳海沟是“the deepest part of the world's oceans”（世界海洋最深处），而非“中心”（center）。选项A混淆概念。

选项C（错误）

“untouched by human activity”（未受人类活动影响）与文章内容矛盾。文中通过污染物的发现，说明人类活动已对海沟造成影响。

选项D（错误）

“profoundly explored”（被深入探索）不符合事实。文中提到“Scientists have only recently explored it”（科学家仅最近开始探索），说明研究仍有限。