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
2010-01-15
39
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 does when it carries faint noise from a patient’ s chest to a doctor’ s ear. This focusing is the main reason why even relatively weak sounds in the ocean, especially low-frequency ones, can often travel thou- sands 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
根据第三段的“…its global network of underwater listening system built over the decades to track the ships of potential enemies.”,可以看出这套系统最初是为了“trace and locate enemy vessels”而建立的,所以,A 符合题意。
转载请注明原文地址:https://jikaoti.com/ti/qybMFFFM
0
专业英语四级
相关试题推荐
Self-discipline:theFoundationofProductiveLivingI.Issuestobenoticedatthethoughtofself-disciplineA.Troublesf
FourreasonsthatrosyNovemberjobsreportwasevenbetterthanitseemed.It’simportantnottomaketoomuchoutofasingl
A、Equalfundingforeverystudent.B、Astandardfundingrateplusloadingforthedisadvantaged.C、Anflexiblefundingsystemac
A、Oneyear.B、Threeyears.C、Fouryears.D、Threetosevenyears.A细节题。四个选项在访谈中都出现过,关键是找出符合题意(diplomacourses)的选项。关于证书类课程,受访者提到:D
HowtoWriteaResearchReportAstandardformatwillhelpreaderstolocatetheinformationtheywantquickly.Itistruet
TenBadListeningHabitsI.CallingtheSubjectDull—Goodlistenerswillhuntforsomething【T1】______II.【T2】______th
ScientistsareinterestedinMarsbecause_______________.
Howoldareseniorcitizens?
WhenRodLavergotbehind,hewould______.
WhenRodLavergotbehind,hewould______.
随机试题
设有关系R(A,B,C)和S(B,C,D),则的属性个数是()
确定病毒型别可采用的试验有
逆转录酶具备而一般DNA聚合酶不具备的活性是
A.Na+B.葡萄糖C.白蛋白D.球蛋白E.纤维蛋白血液凝固的实质是生成了
焦山楂长于
慢性粒细胞白血病慢性期的临床特点是
患儿女,生后7天,诊断为新生儿黄疸,收入院行蓝光治疗。光疗时,护士应特别注意
某省移动公司多次接到投诉,平原地区某村口附近手机信号显示只有一格,且经常掉线,下列措施中,可直接改善现状的措施有()。
下列语言中,属于职业忌语的有()。
A、 B、 C、 D、 BPowerBuilder的主要特点包括:①专业的客户/服务器应用开发工具②全面支持面向对象开发③使用专门接口或ODBC,可同时支持与多种数据库连接④提
最新回复
(
0
)