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
2009-04-23
71
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(爆发) 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.
选项
A、an effort to protect an endangered marine species
B、the civilian use of a military detection system
C、the exposure of a U.S. Navy top-secret weapon
D、a new way to look into the behavior of blue whales
答案
B
解析
文章第一段由跟踪蓝鲸引出话题。第一、二段讲述了生物学家运用海军监听系统取得的研究成果。第三、四、五段介绍了地球科学家以及其他科学家也已经或正在利用军方的设备进行各自的研究。第六段讲述了声音在水中传播的原理。综上所述,本篇主要讲的是一种军事探测系统被民用科学界运用于科研的话题,故B正确。
转载请注明原文地址:https://kaotiyun.com/show/YMC7777K
0
大学英语四级
相关试题推荐
A、Themajorityofpeoplewereagainstit.B、Manycustomersagreedtoperformit.C、Morepeopledidbusinesswiththerestaurant.
A、Agirlhaslivedinatreeforamonth.B、Thewholeforestwillbemissing.C、Peopletiethemselvestotrees.D、Theloggingin
A、Onemonthpaidvacation.B、Payraiseafterayear.C、Chancesofpromotion.D、Reasonabletraining.C
A、TowarnpeoplenottodoittoooftenB、Tosuggestpeoplekeepcoolafterbeingcheated.C、Toadvisepeoplethinkenoughbefor
A、Peoplearemoreawareofreadingthanbefore.B、Peopleareabletogetinformationmoreeasily.C、Peoplespendmuchlesstime
A、Thestudyresearchednearly2,000people.B、MostoftheindividualsinthestudyarefromAsia.C、Thestudycomparedrelateds
A、Allwhalingisbad.B、Commercialwhalingisimmoral.C、Whalingshouldbelimitedonlyforfood.D、TheIWCshouldbereplaced.
BossesSay"Yes"toHomeWorkA)Risingcostsofofficespace,timelosttostressfulcommuting,andaslowrecognitionthatwo
A、Futureproductdistribution.B、Localemploymentpolicies.C、Roadandraillinksforsmalltowns.D、Skilledworkforceinthehi
A、FrancelaunchedthelargestEuropeanartsfundinginitiative.B、CreativeEuropegave2.4billiondollarsto300,000artists.C
随机试题
对子宫有影响的前列腺素主要包括_____________和_____________,对非妊娠子宫_____________使其收缩,_____________使其松弛。
【背景资料】某房屋建筑工程,建筑面积6000m2,钢筋混凝土独立基础,现浇钢筋混凝土框架结构,填充墙采用蒸压加气混凝土砌块砌筑。根据《建筑工程施工合同(示范文本)》(GF一2013一0201)和《建设工程监理合同(示范文本)》(GF一2012
某校学生甲和乙因贪玩上网,上学迟到了半个多小时。班主任王老师非常生气,对他们进行了严厉批评并责令他们写检查,不准进教室上课。两个学生趁王老师不注意跑到学校附近的小河洗澡,结果学生甲溺水而死。请问:王老师应负什么法律责任?说明理由。
压力性尿失禁可见急迫性尿失禁可见
关于乳腺MRI检查技术描述正确的是
A、风寒袭肺B、风热犯肺C、风燥伤肺D、痰湿蕴肺E、肝火犯肺因情绪波动症状增减的咳嗽一般见于
下列有关网络图的表述中,正确的是()。
从会计电算化实现的功能来看,会计电算化主要内容分为()。
检错重发方式(ARQ)内层使用FEC,纠正随机差错,减少重发次数,但外层使用ARQ,重发无法纠正突发差错。()
A-----SchoolZoneJ-----MaintenanceinProgressB-----VendorsProhibitedK-----OutofServiceC---
最新回复
(
0
)