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
66
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.
The underwater listening system was originally designed ______.
选项
A、to trace and locate enemy vessels
B、to monitor deep-sea volcanic eruptions
C、to study the movement of ocean currents
D、to replace the global radio communications network
答案
A
解析
海底监听设备原本用于军事领域对敌舰的追踪和定位。
转载请注明原文地址:https://kaotiyun.com/show/TCtd777K
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
Accordingtothespeaker,whatshouldthelistenersdoassoonaspossible?
Payandproductivity,itisgenerallyassumed,shouldberelated.Buttherelationshipseemstoweaken【C1】______peoplegetolder
Morethan30,000driversandpassengerswhositinthefrontofthevehiclesarekilledorseriouslyinjuredeachyear.Ataspe
HumanintelligenceandtheIQscalesusedtomeasureitonceagainarebecomingthefocusoffierydebate.Asargumentrages
WilliamShakespearedescribedoldageas"secondchildishness"—noteeth,noeyes,notaste.Inthecaseoftastehemay,musicall
Inthe21stcenturythere’snodoubtthatfrighteningnewinfectiousdiseaseswillappear.Todaynewvirusesarecomingoutofn
WilliamShakespearedescribedoldageas"secondchildishness"—noteeth,noeyes,notaste.Inthecaseoftastehemay,musicall
Inthe21stcenturythere’snodoubtthatfrighteningnewinfectiousdiseaseswillappear.Todaynewvirusesarecomingoutofn
Inthe21stcenturythere’snodoubtthatfrighteningnewinfectiousdiseaseswillappear.Todaynewvirusesarecomingoutofn
随机试题
________是物质的根本属性和存在方式。时间是物质运动的________,空间是物质运动的________。
《印花税暂行条例》规定对权利许可证照和其他营业帐簿按件定额贴()
免疫电泳技术的实质是
A、患者男性,38岁,排便次数增多10余年,粪便呈糊状,无脓血,有时有黏液,进食辛辣食物后加重B、患者女性,26岁,间断脓血便3年,加重1个月。多次粪便培养阴性,抗生素治疗无效C、患者男性,60岁,左下腹痛4个月,便血1个月,体重减
在心理治疗工作中,治疗对象有伤害他人的情况时,应该采取的措施是
根据《招标投标法实施条例》规定,下列情形中,属于投标人相互串通投标的是()。
中国证券投资基金业协会成立于()年7月。
某企业批量生产一种零件,投产批量为6件,经过4道工序加工,按照加工顺序,单件每道工序作业时间依次为20分钟、10分钟、25分钟、15分钟,假设零件移动用时为零。根据以上资料,回答下列问题:将一个批次的该种零件全部生产出来,工序间、搬运次数最多
甲股份有限公司(以下简称“甲公司”)2×15年发生的有关交易或事项中,会计处理与所得税处理存在差异的包括以下几项:(1)1月1日,甲公司以3800万元取得对乙公司20%股权,并自取得当日起向乙公司董事会派出1名董事,能够对乙公司财务和经营决策施加重大影
有机磷农药的主要急性毒性是()。
最新回复
(
0
)