首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
It is hard to track the blue whale, the ocean’s largest creature ,which has almost been killed off by commercial whaling and is
It is hard to track the blue whale, the ocean’s largest creature ,which has almost been killed off by commercial whaling and is
admin
2011-02-28
25
问题
It is hard to track the blue whale, the ocean’s largest creature ,which has almost been killed off by commercial whaling and is now listed as an endangered species. Attaching radio devices to it is difficult, and visual sightings are too unreliable to give real insight into its behavior.
So biologists were delighted early this year when, with the help of the Navy ,they were able to track a particular blue whale for 43 days, monitoring its sounds. This was possible because of the Navy’s formerly top-secret system of underwater listening devices spanning the oceans.
Tracking whales is but one example of an exciting new world just opening to civilian scientists after the cold war as the Navy starts to share and partly uncover its global network of underwater listening system built over the decades to track the ships of potential enemies.
Earth scientists announced at a news conference recently that they had used the system for closely monitoring a deep-sea volcanic eruption for the first time and that they plan similar studies.
Other scientists have proposed to use the network for tracking ocean currents and measuring changes in ocean and global temperatures.
The speed of sound in water is roughly one mile a second-slower than through land but faster than through air. What is most important, different layers of ocean water can act as channels for sounds, focusing them in the same way a stethoscope(听诊器) does when it carries faint noises from a patient’s chest to a doctor’s ear. This focusing is the main reason that even relatively weak sounds in the ocean, especially low-frequency ones, can often travel thousands of miles.
Which of the following is true about the U. S. Navy underwater listening network?
选项
A、It is now partly accessible to civilian scientists.
B、It has been replaced by a more advanced system.
C、It became useless to the military after the cold war.
D、It is indispensable in protecting endangered species.
答案
A
解析
关于美国海军海底监听体系,文中第三段有明确说明的是这种技术现在部分地向民用研究科学家开放。
转载请注明原文地址:https://kaotiyun.com/show/GCtd777K
本试题收录于:
公共英语三级笔试题库公共英语(PETS)分类
0
公共英语三级笔试
公共英语(PETS)
相关试题推荐
It’salmostanarticleoffaith:yourbestallyinthefightagainstcancerisadoggedlyoptimisticoutlook.Anditwouldseem
【T1】Whiletherearealmostasmanydefinitionsofhistoryastherearehistorians,modernpracticemostcloselyconformstoone
Thetimeforsharpeningpencils,arrangingyourdesk,anddoingalmostanythingelseinsteadofwritinghasended.Thefirstdra
Thetimeforsharpeningpencils,arrangingyourdesk,anddoingalmostanythingelseinsteadofwritinghasended.Thefirstdra
Inthe21stcenturythere’snodoubtthatfrighteningnewinfectiousdiseaseswillappear.Todaynewvirusesarecomingoutofn
Inthe21stcenturythere’snodoubtthatfrighteningnewinfectiousdiseaseswillappear.Todaynewvirusesarecomingoutofn
Inthe21stcenturythere’snodoubtthatfrighteningnewinfectiousdiseaseswillappear.Todaynewvirusesarecomingoutofn
Whatisthespeakermainlydiscussing?
Inthe21stcenturythere’snodoubtthatfrighteningnewinfectiousdiseaseswillappear.Todaynewvirusesarecomingoutofn
Inthe21stcenturythere’snodoubtthatfrighteningnewinfectiousdiseaseswillappear.Todaynewvirusesarecomingoutofn
随机试题
患者,女,77岁。突发剧烈头痛、恶心、呕吐6小时。体检:血压190/110mmHg,口角右偏,左侧鼻唇沟变浅,伸舌左偏,左侧偏瘫。问题1:病变部位可能是
真武汤主治二妙散主治
瘀血的病症特点,哪种说法不准确
外科病人最易发生水和钠代谢紊乱是
根据《中华人民共和国商业银行法》的规定,商业银行破产清算时的财产分配适用下列哪一种顺序?
基金托管人召集基金份额持有人大会,必须披露的事项不包括()。
某工业企业大量生产甲、乙两种产品。该企业采用品种法计算产品成本,适用的增值税税率为13%。2018年5月份,该企业发生的有关经济业务如下:(1)5月份开始生产甲、乙产品,当月投产甲产品270件,耗用材料4800千克;投产乙产品216件,耗用材料
让一个吸烟上瘾的人扮演因吸烟患肺癌而接受治疗的病人,之后他戒了烟。这一情景中对戒烟起作用的主要因素是()
已知三位青年小刘、小陈、小李的年龄各不相同。有人问到年龄时他们分别回答如下:(1)小刘说:“我22岁,比小陈小2岁,比小李大1岁一”(2)小陈说:“我不是年龄最小的,小李比我小3岁,小李是25岁。”(3)小李说:“我比小刘年龄小,小刘23岁,小陈比小
路由器转发分组上根据报文分组的
最新回复
(
0
)