单选题 {{B}}Passage Six{{/B}}
The sound of gunshots has become an all-too-familiar and unwelcome occurrence in many communities across the nation. When shots ring out, 911 calls from worried citizens may come from a large area. Unfortunately, even with numerous reports, police are often frustrated in their efforts to silence this gunfire because they cannot pinpoint the location of gunshots rapidly. A U.S. Geological Survey (USGS) scientist recognized that sound waves traveling through the air away from a gunshot are basically similar to the sound waves traveling through the ground away from an earthquake. Scientists then have adapted their methods for quickly finding the exact source of an earthquake to the problem of locating gunshots.
Field testing of a gunshot--locating system inspired by earthquake technology began in 1995. After only a few weeks of testing and improving the Software, the system was locating many signals that were clearly associated with gunfire. Automatic weapons fire was the easiest to identify because of the regular time interval between individual shots. The system was more sensitive during the night, when there was less background noise from traffic and other urban activity. By the last spring, the system was undergoing final acceptance trials. Captain Jim Granucci of the Redwood City Police Department stated that "even before the system was in use, the number of illegal gunshots declined as word of its existence spread".
In this test the gunshot-locating system worked remarkably well, and according to Commander Dominick Peloso of the Menlo Park Police Department, "This system, when fully developed, holds great promise for assisting police in controlling and reducing violent crime." When the results of the test were made public, there was an enthusiastic response from San Francisco Bay area residents, who asked local government officials to implement such systems in their communities. Interest was also expressed by private firms and law enforcement agencies both in California and elsewhere in the nation. Robert Showen, founder of a company that is now marketing a gunshot-locating system, said, "The USGS test demonstrated beyond a doubt that the concept was feasible and could be implemented quickly. Without this test, I would have been hesitant to invest in the development of my product."
单选题 The problem of gunfire is difficult to solve because ______.
【正确答案】 D
【答案解析】文章第1段指出警察不能立即查明枪击的地点,故选项D正确。
单选题 It can be learned that the gunshot-locating system ______.
【正确答案】 B
【答案解析】文章第2段提到晚上由于没有其他干扰,系统反映尤为敏锐,可知选项B正确。
单选题 Testing of the gunshot-locating system ______.
【正确答案】 C
【答案解析】第3段第1句指出worked remarkably well以及后面的叙述,故选项C正确。
单选题 Which of the following best describes people's attitude toward the gunshot-locating system ?
【正确答案】 A
【答案解析】第3段提到residents要求政府给他们所在的区安装此系统,private firms and law enforcement agencies也很感兴趣,所以选A。
单选题 This story of the development of a gunshot-locating system shows ______.
【正确答案】 D
【答案解析】由第1段可知,此系统是由地震预测系统的想法转化而来的,故D项正确。