《sat阅读培训资料》由会员分享，可在线阅读，更多相关《sat阅读培训资料（6页珍藏版）》请在金锄头文库上搜索。
1、sat阅读精品文档Virtually everything astronomers known about objects outside the solar system is based on the detection of photons-quanta of electromagnetic radiation. Yet thereis another form of radiation that permeates the universe:(5) neutrinos. With (as its name implies) no electric charge,and negligib
2、le mass, the neutrino interacts with other particles so rarely that a neutrino can cross the entireuniverse, even traversing substantial aggregations of matter, without being absorbed or even deflected. Neu-(10)trinos can thus escape from regions of space where light and other kinds of electromagnet
3、ic radiationare blockedby matter. Furthermore, neutrinos carry with theminformation about the site and circumstances of their production: therefore, the detection of cosmic neutrinos(15)could provide new information about a wide variety of cosmic phenomena and about the history of the uni-verse.But
4、how can scientists detect a particle that interacts so infrequently with other matter? Twenty-five years(20)passed between Paulis hypothesis that the neutrino existed and its actual detection: since then virtually all research with neutrinos has been with neutrinos createdartificially in large parti
5、cle accelerators and studiedunder neutrino microscopes. But a neutrino telescope,(25) capable of detecting cosmic neutrinos, is difficult to co-nstruct. No apparatus can detect neutrinos unless it isextremely massive, because great mass is synonymous with huge numbers of nucleons (neutrons and proto
6、ns),and the more massive the detector, the greater the pro-(30) bability of one of its nucleons 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 detectin
7、g cosmic neutrinos by harnessing the(35) mass of the ocean. Named DUMAND, for Deep Under- water Muon and Neutrino Detector, the project calls for placing an array of light sensors at a depth of five kilo- meters under the ocean surface. The detecting medium is the seawater itself: when a neutrino in
8、teracts with a (40)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 sea- water above the sensors will shield them from the interf- ering effects of other high-energy particles r
9、aining down (45) through the atmosphere.The strongest motivation for the DUMAND project is that it will exploit an important source of informationabout the universe. The extension of astronomy fromvisible light to radio waves to x-rays and gamma rays (50) never failed to lead to the discovery of unu
10、sualobjects such as radio galaxies, quasars, and pulsars. Each of these discoveries came as a surprise. Neutrino astronomy will doubtless bring its own share of surprises.1. Which of the following titles best summarizes the passage as a whole?(A) At the Threshold of Neutrino Astronomy(B) Neutrinos a
11、nd the History of the Universe(C) The Creation and Study of Neutrinos(D) The DUMAND System and How It Works(E) The Properties of the Neutrino2. With which of the following statements regarding neutrino astronomy would the author be most likely to agree?(A) Neutrino astronomy will supersede all prese
12、nt forms of astronomy.(B) Neutrino astronomy will be abandoned if the DUMAND project fails.(C) Neutrino astronomy can be expected to lead to major breakthroughs in astronomy.(D) Neutrino astronomy will disclose phenomena that will be more surprising than past discoveries.(E) Neutrino astronomy will
13、always be characterized by a large time lag between hypothesis and experimental confirmation.3. In the last paragraph, the author describes the development of astronomy in order to(A) suggest that the potential findings of neutrino astronomy can be seen as part of a series of astronomical successes(
14、B) illustrate the role of surprise in scientific discovery(C) demonstrate the effectiveness of the DUMAND apparatus in detecting neutrinos(D) name some cosmic phenomena that neutrino astronomy will illuminate(E) contrast the motivation of earlier astronomers with that of the astrophysicists working
15、on the DUMAND project4.According to the passage, one advantage that neutrinos have for studies in astronomy is that they(A) have been detected for the last twenty-five years(B) possess a variable electric charge(C) are usually extremely massive(D) carry information about their history with them(E) are very similar to other electromagnetic particles5. According to the passage, the primary use of the apparatus mentioned in lines 24-32 would be to(A) increase the mass of a neutrino(B) interpret the info
