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
The Exploding Lakes of Cameroon What comes to mind when you think of a lake? You probably imagine a pretty scene with blue w
The Exploding Lakes of Cameroon What comes to mind when you think of a lake? You probably imagine a pretty scene with blue w
admin
2014-03-13
74
问题
The Exploding Lakes of Cameroon
What comes to mind when you think of a lake? You probably imagine a pretty scene with blue water, birds, and fish. For the people in the northwestern Cameroon, however, the image is very different. For them, lakes may mean terrible disasters. In 1984, poisonous gases exploded out of Lake Monoun and came down into the nearby villages, killing thirty-seven people. Two years later, Lake Nyos erupted. A cloud of gases rolled down the hills and into the valleys and killed 1, 700 people.
Lake Nyos and Lake Monoun are crater(火山口)lakes. They were formed when water collected in the craters of old volcanoes. The volcanoes under Lake Nyos and Lake Monoun are not active anymore. However, poisonous gases from the center of the earth continue to flow up through cracks in the bottom of the lake. This is normal in a crater lake. In most crater lakes, these gases are released often because the water "turns over" regularly. That is, the water from the bottom of the lake rises and mixes with the water at the top, allowing the gases to escape slowly.
However, in Lakes Nyos and Monoun, there is no regular turning over. No one knows the reason for this fact, but as a result, these lakes have more gases trapped at the bottom than other crater lakes. In fact, scientists who have studied Lakes Nyos and Monoun have found 16, 000 times more gases. When a strong wind , cool weather, a storm, or a landslide(滑坡)causes the water to turn over suddenly, the gases escape in a violent explosion.
In the past, no one knew when the gases might explode, so there was no way for the villagers to escape disaster. Now scientists from the United States, France, and Cameroon have found a way to reduce the gas pressure at the bottom of Lake Nyos. They stood a 672-foot plastic pipe in the middle of the lake, with one end of the pipe near the bottom and the other end in the air. Near the top of the pipe, the team put several holes that could be opened or closed by a computer. Now, when the gas pressure gets too high, the holes are opened and some of the gas-filled water shoots up through the pipe into the air like a fountain. With less pressure, a disastrous explosion is much less likely. However, the scientists are not sure that one pipe will be enough to prevent explosions. They hope to put in others soon and they plan to install a similar pipe and a computer system at Lake Monoun as well.
To protect people nearby until all of the pipes are in place, the scientists have installed early warning systems at both lakes. If the gas pressure rises to a dangerous level, computers will set off loud sirens(警报)and bright lights to warn the people in the villages. In that way, they will have time to escape from the dangerous gases.
A team of scientists has______.
选项
A、erected a pressure-releasing pipe in the lake
B、identified the gases at the bottom of the lake
C、built a beautiful fountain near the lakes
D、removed all dangerous gases from the lakes
答案
A
解析
根据第四段第三句“They stood a 672一foot plastic pipe in the middle of the lake,with oneend of the pipe near the bottom and the other end in the air.”可知,该科学家团队在湖里立了一根管子,管子的一端在湖底,另一端在空中。这样做是在利用连通器的原理来减小湖底压强,因此A项正确。
转载请注明原文地址:https://kaotiyun.com/show/koGd777K
本试题收录于:
职称英语理工类A级题库职称英语分类
0
职称英语理工类A级
职称英语
相关试题推荐
DriedFoodsCenturiesago,mandiscoveredthatremovingmoisture(51)foodhelpedtopreserveit,andthattheeasiestwaytodot
DriedFoodsCenturiesago,mandiscoveredthatremovingmoisture(51)foodhelpedtopreserveit,andthattheeasiestwaytodot
Abouttwentyyearsago,allimportantresourcesinourcountrywereallocatedbythecentralgovernment.
HighwaysintheUSTheUnitedStatesiswell-knownforitsnetworkofmajorhighwaysdesignedtohelpadrivergetfromoneplac
AKripke’sResearchToo1BDangersofHabitualShortagesofSleepCCriticismonKripke’sReportDAWayofOvercomingInsom
Whatcountryhasmorehighest-ratingcompaniesintheworldthananyothercountryhas?Whatisthewriterworryingabout?
HowtoStayYoungIfyouwanttostayyoung,sitdownandhaveagoodthink.ThisistheresearchfindingbyateamofJapan
ThefirstnavigationallightsintheNewWorldwereprobablylanternshungatharborentrances.Thefirstlighthousewasputup
TakingaNapduringtheDayMedicalexpertssaymostAmericansdonotgetenoughsleep.TheysaymoreAmericansneedto【51】
A.GoodresultsB.AnancientskillC.GainingattentionD.MemorytricksE.AlectureonmemorytechniquesF.Waystoimpr
随机试题
“盛年不重来,一日难再晨”,这个谚语说的是()
尿道耻骨下弯是恒定的。
人体软组织平均声速是
下列哪项不是引起低血钙的原因
某混凝土工程,9月份计划工程量为5000m3,计划单价为400元/m3,而9月份实际完成工程量为4000m3,实际单价为410元/m3,则该工程9月份的进度偏差为( )万元。
下列关于我国商业银行计算资本充足率、核心资本充足率时扣除项的说法中,不正确的是()。
下列关于营运资本筹资策略的说法中,不正确的有()。
跳远比赛中哪些情况属于犯规?
太阳风暴是指太阳因能量增加而向空间释放大量高速运行的(),它们可能对短波无线电信号的传播造成严重影响。
程序中若有如下说明和定义语句charfun(char*);main(){char*s="one",a[5]={0},(*f1)()=fun,ch;}以下选项中对函数fun的正确调用语句是
最新回复
(
0
)