单选题 Virtually everything astronomers know about objects outside the solar system is based on the detection of photons-quanta of electromagnetic radiation. Yet there is another form of radiation that permeates the universe: neutrinos. With (as its name implies) no electric charge, and negligible mass, the neutrino interacts with other particles so rarely that a neutrino can cross the entire universe, even traversing substantial aggregations of matter, without being absorbed or even deflected. Neutrinos can thus escape from regions of space where light and other kinds of electromagnetic radiation are blocked by matter. Not a single, validated observation of an extraterrestrial neutrino has so far been produced despite the construction of a string of elaborate observatories, mounted on the earth from Southern India to Utah to South Africa. However, the detection of extraterrestrial neutrinos are of great significance in the study of astronomy. Neutrinos carry with Their information about the site and circumstances of their production; therefore, the detection of cosmic neutrinos could provide new information about a wide variety of cosmic phenomena and about the history of the universe.
How can scientists detect a particle that interacts so infrequently with other matter? Twenty-five years passed between Pauli's hypothesis that the neutrino existed and its actual detection; since then virtually all research with neutrinos has been with neutrinos created artificially in large particle accelerators and studied under neutrino microscopes. But a neutrino telescope, capable of detecting cosmic neutrinos, is difficult to construct. No apparatus can detect neutrinos unless it is extremely massive, because great mass is synonymous with huge numbers of nucleons (neutrons and protons), and the more massive the detector, the greater the probability of one of its nucleon's reacting with a neutrino. In addition, the apparatus must be sufficiently shielded from the interfering effects of other particles.
Fortunately, a group of astrophysicists has proposed a means of detecting cosmic neutrinos by harnessing the mass of the ocean. Named DUMAND, for Deep Underwater Muon and Neutrino Detector, the project calls for placing an array of light sensors at a depth of five kilometers under the ocean surface. The detecting medium is the sea water itself: when a neutrino interacts with a particle in an atom of seawater, the result is a cascade of electrically charged particles and a flash of light that can be detected by the sensors. The five kilometers of seawater above the sensors will shield them from the interfering effects of other high-energy particles raining down through the atmosphere.
The strongest motivation for the DUMAND project is that it will exploit an important source of information about the universe. The extension of astronomy from visible light to radio waves to x-rays and gamma rays never failed to lead to the discovery of unusual objects such as radio galaxies, quasars, and pulsars. Each of these discoveries came as a surprise. Neutrino astronomy will doubtlessly bring its own share of surprises.

单选题 "escape from"(Line 6, Para. 1) can be substituted for

【正确答案】 A

【答案解析】本题问第一段第六行的“escape from”可用什么来代替。首段第四句谈到“Neutrinos can thus escape from regions of space where light…are blocked by matter”，由本句中的“thus”可知本句是承接上句内容而说的。而上句谈到“…even traversing substantial aggregations of matter，without being adsorbed or even deflected”，也就是说中微子可以穿透物质，而不会被吸收，甚至不会偏斜。由此可以推出，第四句中“escape from”也是指从“regions of space”穿过去，而光等电磁辐射却会被阻隔住(blocked)。故[A]“穿过”正确。实际上中微子可以穿过物质(比如人体)，而光子等粒子则会被物质阻挡住，下文中谈到要对探测中微子的设备进行屏蔽，使其不受其他微粒子的影响，正是利用别的微粒子会被物质(比如海水)阻挡住，而中微子则会笔直穿过这一特性。
[B]绕过：强干扰项。文意是指中微子可以从物质中穿过(traversing)，而不是说遇到物质集团从旁边绕过去。
[C]相互作用：这里是指不与物质相互作用，而是从物质中间直接穿过去。
[D]源于：文中原意是说中微子能穿越空间，是因为它不受该空间内物质的束缚，而并非是“起源”于该物质。

单选题 What kind of neutrinos would be most useful to astronomers?

【正确答案】 D

【答案解析】本题问哪种中微子对天文学家最有用。首段末句说“中微子携带了关于其产生地和产生环境的信息，因此……”，(其中“of their production”指的并不是中微子的产品，而是指它的诞生。)正是这些信息对天文学有着重要的意义(…are of great significance in the study of astronomy)。跨越遥远的时空而来的中微子无疑载有大量信息。故[D]“穿越很长的时空”正确。
[A]没有电荷，质量很小；[C]不受物质的控制：这些都是中微子本身的普遍性质，并不是天文学家所刻意寻找的。
[B]实验室里人工制造的中微子：第二段谈到粒子加速器产生的中微子，这属于人工制造的中微子，但因为它是人工制造的，反映不出宇宙的信息，所以并不是天文学家所需要的。

单选题 From the third paragraph, besides shelter, the seawater is used as

【正确答案】 C

【答案解析】本题问从第三段可知，除屏蔽作用外，海水还起到什么作用。文章第三段介绍了DUMAND计划，其中海水有两个作用：一是屏蔽掉其他高能粒子(…shield them from the interfering effects of other high-energy particles…)，二是用作反应物与中微子作用(…a neutrino interacts with a particle in an atom of seawater，…)。agent的意思是“反应物，试剂”，故[C]正确。
[A]检测器：在实际检测过程中，首先是中微子与海水作用，然后被传感器探测到(…can be detected by the sensors)。即：海水+sensor=detector。
[B]传感器：在海底安放sensors，但海水本身不是sensor。
[D]溶剂：solvent是“溶剂”的意思，虽然文中含糊地说海水是“detector medium”，但实验者并没有把它作为溶剂去稀释中微子。

单选题 Which of the following is the most desirable site where cosmic neutrinos can be easily detected?

【正确答案】 B

【答案解析】本题问下面哪个是简易检测宇宙中微子最理想的场所。文章二、三两段段末都出现了“shield”一词，说明在探测中微子时要屏蔽掉其他粒子的干扰，在DUMAND计划中，海水就是屏障物质。密封的火山洞与此相似，既然是火山洞，深度肯定没问题，而且岩石就是理想的屏蔽物，故[B]“密封的火山洞”可作为检测中微子的场所。
[A]具有巨大检测器的实验室：其错误在于“labs”一词，虽然文章并没有说什么样的条件可以屏蔽干扰，但在 DUMAND计划中用的是5000米深的海水，可见这是一般实验室无法办到的。
[C]真空箱：vacuum是障眼法，排除此项的理由与[A]相似。
[D]浅的咸水湖：文中用做屏蔽的海水深度是5000米，而比较浅的湖深度不够，无法屏蔽宇宙的其他粒子，因此不适合作为检测中微子的场所。

单选题 Why is it difficult to detect neutrinos?

【正确答案】 C

【答案解析】本题问为什么中微子难于检测。文章第二段说明探测中微子是困难的，其首句“How can…matter?”就暗示了答案：正是因为中微子“interact so infrequently with other matter”才导致其难以被俘获。故[C]“中微子极少与其他粒子相互作用”正确。
[A]中微子可以穿过整个宇宙；[B]中微子可以逃逸不同的空间：此二项都是由“Neutrinos seldom interact with other particles”这一根本原因引起的，它们与“it is difficult to detect neutrinos”皆为结果，三者是并列的关系。
[D]中微子在宇宙中数量很少：原文“the neutrino interacts with other panicles so rarely…”中rarely是副词，说中微子相互作用概率低，并不是说其数量少。