首页
财务会计
医药卫生
金融经济
考公考编
外语考试
学历提升
职称考试
建筑工程
IT考试
其他
登录
职称考试
The Exploding Lakes of Cameroon What comes to mind when you think of a lake?...
The Exploding Lakes of Cameroon What comes to mind when you think of a lake?...
admin
2020-12-24
42
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. That way, they will have time to escape from the dangerous gases.
What will happen when Lake Nyos and Lake Monoun explode?
A Water will flow down the hills.
B Poisonous gases will be released suddenly.
C
选项
A strong wind will rise from the lakes.
D The volcanoes will come to life.
答案
B
解析
该题问的是Nyos和Monoun两湖喷发时会出现什么情况?第一段第四至第六句提到,Monoun喷发时有毒气体随之而出。两年后,Nyos湖喷发时也出现类似情况。故B为答案。
转载请注明原文地址:https://ti.zuoweng.com/ti/wmlQKKKQ
相关试题推荐
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
共用题干 TheExplodingLakesofCameroonWhatcomestomindwhenyouthinkofal...
共用题干 TheExplodingLakesofCameroonWhatcomestomindwhenyouthinkofal...
共用题干 TheExplodingLakesofCameroonWhatcomestomindwhenyouthinkofal...
随机试题
关于职业健康安全与环境管理体系中管理评审的说法,正确的是( )。
关于期权保证金,下列说法正确的是()。
稳定分层湖泊中,易缺氧的水层为()
下颌近中舌侧倾斜的末端孤立牙设置圈形卡环时,卡环臂尖端位于基牙的()A.基牙颊侧的倒凹区B.基牙颊侧近中的倒凹区C.基牙近中缺隙侧邻面D.基牙
游客的投诉不论投诉的对象是旅行社、相关接待单位,还是导游自己,导游都应()。A.以和为贵B.以礼相待C.以人废言D.以柔克刚
以下方剂中,桔梗、甘草没有同用的方剂是A:百合固金汤B:止嗽散C:消风散D:血府逐瘀汤E:杏苏散
以下为V-P试验阳性结果的是A:红色B:黄色C:蓝色D:紫色E:绿色
耳轮干枯焦黑为A.肾精亏虚B.鼻渊C.麻疹先兆D.外感风寒E.外感风热
“贮痰之器”指A.心B.肝C.脾D.肺E.肾
治疗痰瘀阻络之中风恢复期和后遗症的是A.人参再造丸B.华佗再造丸C.抗栓再造丸D.益心舒胶囊E.参松养心胶囊